news7.pdf - Isaac Newton Group of Telescopes

NEWSLETTER

No. 7, December 2003

T H E I S A A C N E W T O N G R O U P

O F T E L E S C O P E S

Dear Reader,

Change and evolution are signs of progress, butare not always without pain. The situation at theING telescopes is evolving rapidly. The process ofrestructuring, focussing on making the ING runat a much reduced cost while still delivering top-class service to the astronomical community isour form of evolution. The process will result in asmaller but stronger observatory, based on astrong team of engineers and astronomers.Moreover, new international relations are beingdeveloped, that will set the scene for the future.

An important milestone was reached on May 6th,with the signing in Tenerife of the new

international agreement for the operation of theING telescopes between PPARC, NWO and theIAC. Our new relationship with the IAC holdsthe prospect of stronger future collaborations inscientific programmes and projects. With thispartnership, Spain gains nearly 10% of theavailable telescope time. In return, the financialcontribution from the IAC offsets cost savingsthat were required from the side of the UK.Moreover, the IAC is constructing a world-classIR spectrograph, LIRIS, for the William HerschelTelescope that will be offered to all users of thetelescope, thus adding to the scientific capabilityof the telescope.

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Message from the Director

Above: Picture of the near-infraredimager and spectrograph LIRISmounted on the Cassegrain focus ofthe William Herschel Telescope. Left:LIRIS two-dimensional spectrum of themost distant QSO at z=6.41 (top row).The extracted spectrum is shown inthe top left panel. A fit to the spectrumis also shown, where several broademission lines are identified. The mostintense feature is the CIV line,detected with a S/N ratio of 10. Thespectrum is the co-addition of 5 framesof 850s exposure time each, giving anapproximate total time of 70min. (seearticle by J. A. Acosta Pulido et al. onpage 15).

First Light on LIRIS

With this agreement ING has found anew balance with its three partners thatwill bring scientific benefits for allastronomers as well as a positive outlooktowards a strong collaboration with ourSpanish colleagues. The article in thisNewsletter by the Director of the IAC,Prof Francisco Sánchez, sets out theclear vision on this new collaborationfrom the Spanish perspective.

A second important result ofinternational collaboration in recentmonths has been the development of avery large proposal requesting funds tothe European Community under the

Framework-6 programme. Many areas ofobservational astronomy are combinedwithin this proposal, named OPTICON.The ING telescopes play a prominentrole in the part of the proposal that aimsto foster access to the various telescopeson a truly European scale.

This Newsletter again highlights anumber of scientific successes throughexcellent articles. Also progress onvarious projects is reported here. I trustyou will enjoy this issue.

René G. M. Rutten

No. 7, December 2003 THE ING NEWSLETTER

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The ING Newsletter

ISSN 1575–8958 (printed version)ISSN 1575–9849 (electronic version)Legal License: TF–1959/99

Published in Spain by THE ISAAC

NEWTON GROUP OF TELESCOPES (ING).

Apartado 321; 38700 Santa Cruz de LaPalma; Canary Islands; Spain.Telephone: +34 922 425400Fax: +34 922 425401URL: http://www.ing.iac.es/

Editorial team: Javier Méndez, RenéRutten and Danny Lennon.Consultants: Johan Knapen andCarlos Ortega.Designer: Javier Méndez.Preprinting: Gráficas El Time. Printing: Gráficas Sabater.

The ING Newsletter is primarily publishedon-line at http://www.ing.iac.es/PR//newsletter/ in HTML and PDF format.Notification of every new issue is givenby e-mail using the [INGNEWS] mailinglist. More information on [INGNEWS]can be found on page 31. Requests forone-off printed copies can be emailed toJavier Méndez ([email protected]).

The ING Newsletter is published twice ayear in March and September. If youwish to submit a contribution, pleasecontact Javier Méndez ([email protected]).Submission deadlines are 15 July and15 January.

THE ISAAC NEWTON

GROUP OF TELESCOPES

The Isaac Newton Group ofTelescopes (ING) consists of the4.2m William Herschel Telescope(WHT), the 2.5m Isaac NewtonTelescope (INT) and the 1.0mJacobus Kapteyn Telescope (JKT),and is located 2,350m above sealevel at the Roque de LosMuchachos Observatory (ORM) onthe island of La Palma, CanaryIslands, Spain. The WHT is thelargest telescope of its kind inWestern Europe.

The construction, operation, anddevelopment of the ING Telescopesis the result of a collaborationbetween the United Kingdom andthe Netherlands. The site isprovided by Spain, and in returnSpanish astronomers receive 20 percent of the observing time on thetelescopes. The operation of the siteis overseen by an InternationalScientific Committee, or ComitéCientífico Internacional (CCI).

A further 75 per cent of theobserving time is shared by theUnited Kingdom, the Netherlandsand the Instituto de Astrofísica deCanarias (IAC). The remaining 5per cent is reserved for largescientific projects to promoteinternational collaboration betweeninstitutions of the CCI membercountries.

The ING operates the telescopes onbehalf of the Particle Physics andAstronomy Research Council(PPARC) of the United Kingdom,the Nederlandse Organisatie voorWetenschappelijk Onderzoek (NWO)of the Netherlands and the IAC inSpain. The Roque de Los MuchachosObservatory, which is the principalEuropean Northern hemisphereobservatory, is operated by the IAC.

(Continued from front cover)

The ING BoardThe ING Board oversees the operation,maintenance and development of the IsaacNewton Group of Telescopes, and fosterscollaboration between the internationalpartners. It approves annual budgets anddetermines the arrangements for theallocation of observing time on thetelescopes. ING Board members are:

Prof J Drew, Chairperson – ICLProf T van der Hulst, Vice Chairperson –

Univ. of GroningenDr G Dalton – Univ. of OxfordDr R García López – IACProf T Marsh – Univ. of WarwickDr R Stark – NWODr C Vincent – PPARCDr S Berry, Secretary – PPARC

The ING Director’sAdvisory GroupThe Director’s Advisory Group (DAG)assists the observatory in defining thestrategic direction for operation anddevelopment of the telescopes. It alsoprovides an international perspective andact as an independent contact point for thecommunity to present its ideas. DAGmembers are:

Dr M McCaughrean, Chairperson –Astrophysikalisches Institut Potsdam

Dr M Balcells – IACDr P A James – Liverpool John Moores Univ.Dr N Tanvir – Univ. of HertfordshireDr E Tolstoy – Univ. of Groningen

THE ING NEWSLETTER No. 7, December 2003

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T he Instituto de Astrofísica deCanarias (IAC) opened itsobservatories to the

international scientific community in1979, as a result of the Agreement onCo-operation in Astrophysics. Eversince, its vocation has been to serve asmore than a mere venue for telescopesand instruments from differentcountries. It has gradually becomeinvolved in new telescopes and it hasstrengthened its bonds of co-operationwith the user institutions.

The Isaac Newton Group of Telescopes,pioneer in astronomical observationsat the Roque de los MuchachosObservatory, is one of the mostcomplete and advanced collections ofoptical /infrared telescopes in Europe.For over 20 years, these telescopes havegiven the British, Dutch and Spanishscientific communities the chance tomake state-of-the-art observations,which have made a tremendouscontribution to pushing back thefrontiers of knowledge in many fieldsof astronomy. Discovery of the opticalcounterparts of gamma ray bursts,studies of galaxy formation and thesearch for and characterisation ofbrown dwarfs are but a few of manyexamples we could mention.

The vital role these telescopes haveplayed in the development of Spanishastronomy is beyond doubt. Their valuecan be seen from the fact that manymore observing proposals are submittedto the WHT and INT than can becarried out. On the WHT, four out offive good observing proposals fromSpanish groups cannot be carried outdue to lack of telescope time.

It is well-known that optimum use of10-m telescopes requires medium-sizedtelescopes (between 2 and 4 metres) toact as support and to prepare projectsto be carried out on larger diametertelescopes. With the imminent startof operations of the Gran Telescopio

de Canarias, the ING telescopes willplay an important role.

For this reason, PPARC’s decision toreduce the funding available foroperating the ING telescopes was acause of deep concern for the IAC. Inthe face of this uncertainty andconcerned about the ING’s future, theIAC decided to explore possible waysto reinforce co-operation with the INGto ensure its continuity and toguarantee that its telescopes willcontinue to operate in optimumconditions.

The agreement with PPARC and NWOhas ensured operational continuity ofthe ING, whilst, at the same time,providing additional time for Spanishastronomers. The IAC contributionconsists of qualified staff, astronomersand engineers, plus an infraredimaging spectrograph for the WHT(LIRIS). The overall IAC contributionis equivalent to about half a millioneuros per year. The Spanish astronomycommunity increases its share of INGtelescope time by 9.1% a year. Inparticular, this time is being used toprepare the science that will be donewith the GTC.

Because drafting of the legal texts ofagreements between institutions ofseveral different countries is seldomeasy, formal signing of the agreementhas been delayed. This, however, hasnot prevented the agreement frombeing applied. Since 2002, observingtime has been made available andIAC staff have gradually joined INGtelescope activities. Furthermore, thefirst commissioning of the LIRISinstrument was highly successful, farexceeding the expectations of boththe ING and the IAC.

Spanish astrophysicists have alreadybenefited from the increased access totime on these telescopes, with a startbeing made on several programmesthat were approved after the relevant

announcement of opportunity wasmade to the entire Spanishastronomical community.

We are sure that this agreement willhelp to reinforce co-operation amongour institutions, thus facilitatingincreased collaboration in the futurewithin the “European Research Area”that the European Union is promoting.We are convinced that this willstrengthen astronomy on La Palma,where the exceptional naturalconditions will continue to beattractive for the installation of newgeneration telescopes. This will havea direct impact on Europeanastronomy, particularly if the EuropeanExtremely Large Telescope is finallyinstalled at the Roque de los MuchachosObservatory in the next decade.¤

Francisco Sánchez ([email protected])

IAC Partnership with ING

Francisco Sánchez Martínez (Director IAC)

From top to bottom: IAC in La Laguna(Tenerife), Observatorio del Teide(Tenerife) and Observatorio del Roquede Los Muchachos (La Palma). Bothobservatories are operated by the IAC.


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map out the true masses and shapesof dSph matter distributions.

Draco

With the commissioning of theAUTOFIB2/WYFFOS instrument onthe WHT, it became possible to obtainsimultaneous spectra of about ahundred stars over a one degree field,overcoming the problem of Galacticcontamination near the outer limits ofthe dSphs’ stellar distribution. In fournights in June 2000, we were able tomeasure the velocities of 159 Dracomember stars, extending nearly to theKing tidal radius (Kleyna et al., 2001).From these data, it is apparent thatDraco’s velocity dispersion remains flator even increases with radius, stronglysuggesting the presence of an extendeddark halo. An isotropic Jeans equationmass estimate of the mass containedwithin Draco’s light distribution givesM~108 M , with a mean mass-to-lightratio M/L ≈500 M /L .

By performing a maximum likelihoodfit of Draco to a family of dynamicalmodels parameterised by the halo

SCIENCE

First Evidence for an Extended Dark Halo in the DracoDwarf Spheroidal

Jan T. Kleyna, Mark I. Wilkinson, Gerard Gilmore, N. Wyn Evans (IoA)

O ver the past several years, wehave been engaged in a projectto obtain velocities at large

radii in the Draco and Ursa Minordwarf spheroidal (dSph) galaxies.Draco and UMi are low-luminosity(L≈2 ×105L ) galaxies about 70 kpcfrom the Milky Way. Stellar velocitymeasurements in the centres of Dracoand UMi suggest a central mass-to-light ratio M/L≈102 M /L (Aaronson,1983; Armandroff, Olszewski, & Pryor,1995; Hargreaves et al., 1996). If thisexcess mass takes the form of darkmatter, then Draco, UMi, and otherdSphs with large M/L should beexcellent laboratories in which tostudy structure formation and darkmatter haloes: low mass galaxies likethe dSphs are probably the basiccomponents from which all largerstructures form, and an understandingof the low-mass end of the galaxyspectrum provides an importantconstraint for evaluating Cold DarkMatter (CDM) and other theoreticalmodels of structure formation.

In the past, stellar velocitymeasurements have been concentratedin the cores of dSphs, and dynamicalmodelling has largely been limited tofitting the central velocity dispersionto an isotropic mass-follows-light Kingprofile. However, the assumption thatmass follows light is known to beincorrect for virtually all other galaxies,and the assumption of isotropy masksthe crucial degeneracy betweenanisotropy and mass. Thus, a primeobjective of this work is to obtain stellarvelocities at large projected radii withinDraco and other northern dSphs.Combined with modelling methods thatrelax the assumption that mass followslight and permit varying halo shapes,this new data set should allow us to

shape and anisotropy (Wilkinson et al.,2002), it was possible to lift thedegeneracy between Draco’s mass andorbital anisotropy. In these models, theoverall velocity normalisation was fittedby the projected central dispersion, thehalo shape parameter α could varyfrom from mass follows light (α =1) toconstant density (α = –2), and thelogarithmic anisotropy parameter νcould be radially anisotropic (ν >0) ortangentially anisotropic (ν < 0). Thelikelihood contours of Figure 1 showsthe result of our modelling: Draco isfit best with an isotropic orbitaldistribution in a halo that becomesapproximately isothermal (α ≈0) atlarge radii. Both a mass-follows-lightdistribution and a completely flat halodensity are ruled out at the ~2.5σlevel. The best fit mass, M~ 8×107M ,is similar to the Jeans estimate.

Ursa Minor

Ursa Minor (UMi) resembles Dracoin size, luminosity, and velocitydispersion. Unlike Draco, it is elongatedand appears to have a second peakalong the major axis. Often, this peak

O.

O. O.

Figure 1. Likelihood contoursof the fit of our Draco data tothe two-parameter α,ν modelsof Wilkinson et al. (2002). Thecontours are at enclosed two-dimensional χ2 probabilitiesof 0.68, 0.90, 0.95, and 0.997.The most likely value isindicated by a plus sign. Thetop and right panels of eachplot represent the probabilitydistributions of α and ν ,respectively; the median ofeach distribution isrepresented by a square, andthe triangles show the 1σ ,2σ and (for ν) 3σ limits.

O.O. O.

O.


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is attributed to tidal disruption, thougha plausible mechanism for this hasnot been proposed. In May 2002, weundertook a 4-night AF2/WYFFOSrun to obtain large-radius stellarvelocities in UMi, with the aim offitting for the halo shape and orbitalanisotropy using our α , ν models.However, 2.5 nights were clouded out,and poor seeing limited the quality ofthe data of the remaining 1.5 nights.

Though our data was insufficient fordetailed modelling, we werenevertheless able to obtain a numberof velocities in the vicinity of UMi’ssecond density peak. After combiningour data set with previously publishedUMi velocities, we noted that thevelocity histogram of the clumpappeared narrower than the dispersionof UMi as a whole (Kleyna et al., 2003).Accordingly, we modelled UMi’svelocity distribution as the sum of twoGaussians: a Gaussian subpopulationwith adjustable normalisation, widthand mean, and an 8.8 km s–1 Gaussianrepresenting the bulk of UMi’s stars.We then scanned the face of UMi todetermine where there was a signatureof a kinematical subpopulation. Assuggested by the histograms, only theregion near the second clump containedstatistically significant ( p=99.45%)evidence of a second kinematicalpopulation (Figure 2).

We note that a dynamically coherentpopulation can survive inside a coredhalo, because sinusoidal orbits in the(nearly) harmonic potential of a coredo not diverge over time. However,kinematical substructure would bequickly smeared out if UMi’s halo hada density cusp, as predicted by CDM.Detailed dynamical simulationsdemonstrate that a cold clump couldsurvive for a Hubble time in a5×107 M UMi-like dSph if the halohas a core larger than ~500 pc. If thehalo has a cusp, however, all evidenceof substructure is erased within severalhundred million years.

Summary

Using large-radius velocity dataobtained using AF2/WYFFOS, weshow that the Draco dSph possesses

an anisotropic velocity distribution anda dark halo that is isothermal in thelimit of large radii. In Ursa Minor, weshow that the second peak in thestellar density has a cold kinematicalsignature. This signature stronglysuggests that the feature is a persistentclump sloshing back and forth withina dark matter core, and is inconsistentwith the cusped halos that are predictedby Cold Dark Matter theory.¤

Jan Kleyna ([email protected])

References:

Aaronson, M., 1983, ApJ, 266, L11.

Armandroff, T. E., Olszewski, E. W.,Pryor, C., 1995, AJ, 110, 2131.

Hargreaves, J. C., Gilmore, G., Irwin, M.J., Carter, D., 1996, MNRAS, 282, 305.

Kleyna, J. T., Wilkinson, M. I., Evans, N.W., Gilmore G., 2001, ApJ, 563, L115.

Kleyna, J. T., Wilkinson, M. I., GilmoreG., Evans, N. W., 2003, ApJ, 588, L21.

Wilkinson M. I., Kleyna, J. T., Evans, N.W., Gilmore G., 2002, MNRAS, 330, 778.

R ecent studies of star-formingobjects in the early universe,measuring their clustering

properties and determining theirluminosity functions, have shown thatthese galaxies are key to understandingthe star formation and metalenrichment history of the universeand the role of galactic “super-winds”in regulating the conversion of baryonsinto stars.

In this article, we describe how, usingthe SAURON integral field

spectrograph, we study the formationof the most massive galaxies in theUniverse. The primary target is thebright Ly-α emission line halo in theconspicuous SSA 22 super-cluster atz = 3.07– 3.11 (Steidel et al., 2000).The highly-obscured very luminoussubmillimeter galaxy found bySCUBA near the centre of this haloprobably is an example of a formingmassive elliptical galaxy (Chapmanet al., 2001).

Figure 2. Result of search forkinematic sub-populations in UMi.Coutours are linearly spacedstellar isopleths; the second peakof UMi’s stellar population isvisible above and to the left of thecentre. Gray stars are UMi redgiant branch member stars withmeasured velocities. The filledcircles represent points where amodel with a kinematically coldsub-population is at least 1000times more likely than a modelcomposed of a single 8.8 km s–1

Gaussian. The size of each dot isproportional to the logarithm ofthe relative likelihood.

O.

The SAURON Deep Field: Investigatingthe Diffuse Lyman-αα Halo of “Blob1”in SSA 22

R. G. Bower1, S. L. Morris1, R. Bacon2, R. Wilman1, M. Sullivan1,S. Chapman3, R. L. Davies4, P. T. de Zeeuw5

1: Physics Department, University of Durham. 2: CRAL-Observatoire, Lyon. 3: CaliforniaInstitute of Technology. 4: Dept. of Astrophysics, University of Oxford. 5: Sterrewacht Leiden.


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Using SAURON, we can map thethree-dimensional velocity structureof the SSA 22 ‘blob 1’ halo. This allowsus to probe the nature of the ionisedgas surrounding the SCUBA source,gaining insight into the origin of thediffuse halo (is it primordial materialinfalling onto the central object, ormaterial expelled during a violentstar burst), the mass of its dark matterhalo, and the energetics of any super-wind being expelled from the galaxy.We can also trace the large scalestructure surrounding the centralsource, and investigate whether similarhaloes are surrounding other galaxiesin the field. The answers to thesequestions will allow us to understandhow galaxy formation is regulated inmassive galaxies in the high-redshiftUniverse. They offer key insight intothe “feedback” process and will helpexplain why less than 10% of thebaryon content of the universe everforms into stars (the “cosmic coolingcrisis”; Cen & Ostriker, 1999; Baloghet al., 2001).

This is new ground for the SAURONinstrument. Although it was designedto study the dynamics and stellarpopulations of nearby ellipticalgalaxies, we will show that it can veryeffectively be used to study lowsurface brightness emission featuresonly detectable in long integrations.These observations offer a fore-tasteof the deep field observations thatcan be made with the VIMOS andMUSE integral field spectrographson 8m telescopes.

The Data-Cube

The SAURON instrument is a highthroughput integral field spectrograph(Bacon et al., 2001) that is currentlyoperated on the William HerschelTelescope. It was designed and builtby a partnership between Lyon,Durham and Leiden with the mainobjective of studying the dynamics andstellar populations of early-typegalaxies (de Zeeuw et al., 2002). Itcombines a wide field (41″×33″ sampledat 0.95″) with a relatively high spectralresolution (4 Å FWHM, equivalent toσ =100 kms–1 in the target rest frame).The instrument achieves this by

compromising on the total wavelengthcoverage, which is limited to 4810 to5400 Å. This spatial and spectralsampling ensure that low surfacebrightness features are not swampedby read-out noise. However, the limitedspectral coverage means that it is onlypossible to study the Ly-α emissionfrom systems at redshifts betweenz = 2.95 and 3.45. Fortunately, theSSA 22 supercluster lies within thisredshift range. The sky background isdevoid of strong night sky emission inthe Sauron wavelength range. Forthese observations, the SAURONgrating was upgraded with a VPH unitgiving an overall system throughputof 20%.

Sauron was used to observe the SSA 22source for a total of 9 hours, spreadover 3 nights in July 2002. The rawdata was reduced using the XSauronsoftware. The extraction procedureuses a model for the instrumentaldistortions to locate each of the spectra,and to then extract them using optimalweighting. The extraction process takes

into account the flux overlap betweenadjacent spectra. To remove smallflat-field and sky subtraction residuals,a super-flat was created using theeighteen 30 min individual exposures.This procedure improved the flat fieldaccuracy up to 1 % RMS. Eachindividual datacube was thenregistered to a common spatial locationusing the faint star in the south eastof the field and then merged into thefinal data-cube. To produce the mapof Ly-α emission, we subtract thecontinuum, using a low orderpolynomial fit to the full wavelengthrange. The end result is a 3-D (x, y, λ)map of the Ly-α emission from theregion.

Results

Three dimensional data of this typemust be carefully visualised in orderto extract the maximum informationfrom the data. We started by creatinga colour projection of the data cubeshown in Figure 1. In this view, the

Figure 1. A colour representation of the wavelength shifts of Ly-α emission in thediffuse halo of SSA 22 ‘blob 1’. A simple interpretation of the image is that red, greenand blue channels represent the red-shifted and blue-shifted motions of the ionisedmaterial in the halo. The positions of the two Lyman break galaxies C11 and C15 aremarked, along with the position of the submillimeter source (SMM). The area shownis 37″×46″.


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source close to the centre of the ‘cavity’in the emission structure.

Discussion

Below we divide our results into theseparate features seen in our data anddiscuss some ideas for how we mightinterpret them. The interpretation iscomplicated because Ly-α is a resonantline. Thus shifts in the feature canappear both because of genuine gasmotion and because photons diffusein wavelength to escape from opticallythick regions. In what follows weassume that bulk motion is thedominant source of line broadening.

– The main halo has a complexstructure. Within the broad emission,there are many halo components. Thevariations in line width and velocityare inconsistent with a simpleoutflowing shell. The distribution isbetter modelled by distinct gascomponents, moving relative to eachother with speeds of severalhundred km s–1. One (certainly naive)interpretation of the wavelengthvariations is that they reflect thefree motions of separate gas clumps

bound in a common gravitationalpotential.

– If the above were true, we could usethe magnitude of the velocitydifferences to infer the halo masswithin ~ 75 kpc (or 10″, the typicalradius at which the clumps can beidentified). If we assume that theclumps are on random orbits with aline of sight velocity dispersion of500 km s–1, this suggests a mass oforder 1.3×1013 M , as expected fora small cluster. It is likely, however,that in fact the clumps have a netoutflow or inflow, or are subject todrag from the intergalactic medium(IGM). This makes the mass estimateuncertain.

– Figure 3 shows the relative locationof the emission-line halo and theoptical counterpart of the strongsub-mm source (Chapman et al.,2001; 2003). The overlay suggeststhat the sub-mm source may belocated at the centre of a ‘cavity’ inthe Ly-α emission. There are severalpossible interpretations of this cavity.(1) It may be a genuine cavity inthe ionised gas distribution. Thismight be evidence for a strong windbeing blown away from the central

red, green and blue colour channelshave been created from the data in thewavelength ranges 4976.05, 4964.75,4988.70. Each channel is 5.75Å wide(350 kms–1 in the system rest frame).The image has also been smoothedspatially with a Gaussian of 1″ width.We have marked the positions of theLyman break galaxies, C11 and C15,identified by Steidel et al. (1996) andthe location of the sub-mm sourceidentified by Chapman et al. (2003)(see below). The data-cube canalternatively be viewed as a sequenceof wavelength slices as shown inFigure 2, or these slices can becombined together to make ananimation.

Many striking structures can be clearlyseen in the main halo. The overallwidth of the emission is very broad(~1500 km s–1 FWHM) but separateemission structures can be identified.If we interpret the wavelength shiftas a Doppler shift, the systems differin velocity by a few hundred km s–1.There is significant velocity asymmetryin the emission region around theLyman break galaxy C11 and acrossthe main halo. The morphology ofthe diffuse emission also becomesclear in these velocity slices:particularly interesting is thedepression seen near the centre of thehalo (this is partially filled byredshifted emission), and the diffuseextension of the halo towards thenearby Lyman break galaxy C15.C15 itself is centred in a separate butmuch smaller halo. There is a clearE–W velocity shift across this ‘mini-halo’. We discuss each of thesefeatures below.

The optical counter-part of the sub-mmsource has been identified by Chapmanet al. (2003) after detecting theassociated CO emission. To locatethe emission relative to the SCUBAsource more precisely, we aligned theIFU data cube and the HST STISimage of Chapman et al. using thelocations of the alignment star and theLyman break galaxies C11 and C15.Figure 3 shows the STIS imageoverlayed with the contours of thetotal Ly-α emission. This clearlyshows the location of the sub-mm

O.

Figure 2. A sequence of contour plots showing the changing morphology of the Ly-αemission at different wavelengths. The velocity step between each map is 208 km s–1,with each slice combining a 5.75Å wavelength range so that alternate panels showindependent data. Crosses mark the positions of Lyman break galaxies and thesubmillimeter source. The grid squares have a spacing of 8″.


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sub-mm source. This would obviouslynot be consistent with the moredistant material being discrete gasclumps moving on orbits with theirmotion dominated by thegravitational potential. (2) The cavitymay occur because the ionised gasin this region contains significantdust. As the Ly-α diffuses out ofthe region, it is strongly extincted.This would be consistent withredshifted emission being seen inthis location (this wavelength is notresonantly scattered). Thisexplanation is appealing since weknow that the central SCUBAsource has high extinction. (3) It ispossible that we are seeing theoptical equivalent of Wide AngleTail radio sources, where lineemission is coming from poorlycollimated outflows from a centralgalaxy, which are then deceleratedby the IGM, while the centralsource moves on through the IGM.

– The two other Lyman break galaxiesembedded in the structure appearto have dynamically distinct haloes.This is particularly clear for C15, tothe north of the main halo. Indeedthere is faint emission that bridges

Figure 3. A deep STIS image of the SSA 22 ‘blob 1’ region showing the position for theSCUBA counterpart (Chapman et al., 2003) relative to the total Ly-α emission (contours).The sub-mm source may lie in a 3-D cavity in the emission (compare contours withFigure 1). The Lyman break galaxies C15 and C11 are marked. Their distinct haloesare clearly seen in the 3-D data set.

between C15 and the central halo.A similar feature can also bediscerned around C11. This is asurprising discovery that leads usto consider whether other Lymanbreak galaxies would also haveextended Ly-α haloes.

– The mini-halo around the C15Lyman break galaxy has its owncharacteristic velocity shear pattern.We can identify the morphology ofthis galaxy from the STIS imagingof Chapman et al. (2003). C15 iselongated at roughly 60 degrees(Figure 3) to the velocity shear seenin Ly-α. This, together with themorphology of the emission, makesit unlikely that the shear reflectsthe rotation of a conventional gasdisk. Instead, the shear pattern isreminiscent of the super-windoutflows predicted from proto-galactic disks (Springel & Hernquist,2002), and observed (on a smallerscale) in local starburst galaxiessuch as M82.

Next Steps

These observations clearly demonstratethe ability of deep integral field

spectroscopy to detect low surfacebrightness emission from distantgalaxies in the early universe. Theygive us fascinating insight into thenature and structure of the ionisedhalo of SSA 22-1. It is interesting tonow see how far this powerful newtechnique can be taken. On the onehand it is fundamental to establishwhether the diversity of structureseen in SSA 22-1 is a generic propertyof other highly luminous sub-mmgalaxies, or whether the deep potentialwell of the SSA 22 super-cluster isnecessary to produce emission of thisluminosity and extent. It will also beimportant to determine whether otherLyman break galaxies show mini-haloes similar to C15.

Our observations with the SAURONspectrograph also lay out a path forforthcoming integral fields units. Forexample, OASIS, an adaptive opticsoptimised integral field spectrograph,could be used to complement SAURONby studing the higher surfacebrightness emission line regions ingreater detail. The MUSE spectrographbeing designed for the VLT will offerthe ideal combination of all theseinstruments providing a combinationof wide-field coverage, good spatialresolution and optimal spectral resolution.

Acknowledgments

We thank the SAURON instrumentteam for their support of this program,and for creating an instrument withthe superb sensitivity of SAURON.RGB acknowledges the support of theLeverhulme foundation.¤

References:

Bacon et al., 2001, MNRAS, 326, 23.

Balogh, Pearce, Bower & Kay, 2001,MNRAS, 326, 1228.

Cen & Ostriker, 1999, ApJ, 519, L109.

Chapman, et al., 2001, ApJ, 548, 17.

Chapman et al., 2003, in prep.

de Zeeuw et al., 2002, MNRAS, 329, 513.

Springel & Hernquist, 2003, MNRAS,339, 289.

Steidel, Giavalisco, Dickinson, Adelberger,1996, ApJ, 462, L17.

Richard Bower ([email protected])


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W HT/INTEGRAL observationshave shown a large-diameter(110 pc) supernova remnant

to encircle the position of theUltraluminous X-ray Source (ULX)IC 342 X-1 (Roberts et al., 2003). Weinfer a remarkable initial energyinput to the SNR, at least 2–3 timesgreater than the canonical value foran ‘ordinary’ SNR of 10 51 erg. Inaddition, two regions on the inside ofthe SNR shell are bright in [OIII]λ5007 emission, possibly as the resultof photoionization by the ULX. If thisis the case, the morphology of thenebulosity implies that the X-rayemission of the ULX is anisotropic. Thepresence of the ULX, likely to be ablack hole X-ray binary, within anunusually energetic SNR suggeststhat we may be observing theaftermath of a gamma-ray burst.

Background

Ultraluminous X-ray sources are themost luminous point-like extra-nuclearX-ray sources located coincident withnearby galaxies, displaying X-rayluminosities in excess of 1039erg s–1.Whilst some ULXs are known to beassociated with recent supernovae, themajority appear to show thecharacteristics of accreting black holes(Makishima et al., 2000). However, attheir observed X-ray luminosities theymatch, or in many cases greatly exceed,the Eddington limit for accretiononto a stellar-mass (~10M ) blackhole. ULXs may therefore provideobservational evidence for accretiononto a new, 102–105 M intermediate-mass class of black hole (e.g. Colbert& Mushotzky, 1999). Alternatively,they could constitute the extreme endof the accreting stellar-mass blackhole population, with their highapparent luminosities a result of

either truly super-Eddington X-rayemission (Begelman, 2002), or ananisotropic radiation pattern (e.g. Kinget al., 2001).

One method of investigating the natureof ULXs is through detailed multi-wavelength follow-up observations. Wehave undertaken one such programmeusing the integral field unitINTEGRAL on the William HerschelTelescope to obtain optical spectro-imaging data, through 189 fibres overa 16.5×12.3 arcsecond2 field-of-view,of the immediate environment offourteen nearby ULXs. A crucialelement of this programme is that weuse sub-arcsecond X-ray astrometricdata from NASA’s Chandra X-rayobservatory to locate the ULXs, whichdramatically reduces the confusionproblems inherent to older, lessaccurate X-ray positions. Thisprogramme has already borne fruitwith the detection of the first stellaroptical counterpart to an ULX; a youngstellar cluster coincident with NGC5204 X-1 (Roberts et al., 2001; Goadet al., 2002), which suggests that thisULX may be an extremely luminoushigh-mass X-ray binary. Here, weoutline the results of an observationof the environment of a second ULX,IC 342 X-1, which reveals a verydifferent optical counterpart.

The IC 342 X-1 Nebula

The first observation, on February 1st2001, highlighted a shell-like emission-line nebula in the immediateenvironment of IC 342 X-1 (Figure 1;this nebula, and its SNR-like lineratios, was also detected by Pakull &Mirioni (2003a), who christen it the“tooth” nebula due to its distinctivemorphology). A high [SII]/Hα emission-line ratio of ~1.1 is seen over theextent of the nebula, a classic indicatorthat the nebula is a supernova remnant(SNR). Our new Chandra positionclearly locates the ULX in the centralregions of the nebula, raising theintriguing possibility that the two maybe physically related.

By utilising both the imaging andspectroscopic measurements providedby INTEGRAL, and assuming the SNRis in the pressure-driven snowploughphase (c.f. Cioffi, McKee &Bertschinger, 1988), we were able toplace the constraints on the SNRproperties shown in Table 1. The SNRappears unusually large, with aprojected diameter of at least 110 pc.For comparison, Matonick & Fesen(1997) argue that a typical single SNRwith an initial energy E 51=1 shouldnot remain visible once it has expandedbeyond a diameter of 100pc. The

The Unusual Supernova Remnant Surrounding theUltraluminous X-Ray Source IC 342 X-1

T. P. Roberts1, M. R. Goad2, M. J. Ward1, R. S. Warwick1

1: University of Leicester. 2: University of Southampton.

Figure 1. Narrow-band INTEGRAL images of the environment of IC342 X-1 in the5300–5500 Å continuum band (left), continuum-subtracted Hα +[NII] (centre), andcontinuum-subtracted [SII] (right). The circle represents the uncertainty in the ULX positionrelative to the INTEGRAL data, and each panel is 16.5 ×12.3 arcsecond2 in size.

O.

O.


1 0

unusual size of this SNR can beattributed to an extraordinary initialenergy (assuming a single explosion)of at least 2×E51.

that gamma-ray bursts do occurwhen black holes are formed.

However, there are other possibleorigins for the nebula. It might be theresult of multiple supernovae occurringin a relatively short space of time(~105 yr). This would require apopulation of young stars within thenebula, which future deep opticalcontinuum observations would detectif present. A second alternative origincould be in jets originating in the ULX.A Galactic analogue of such a systemis the W50 nebula, thought to beinflated by the relativistic jets of themicroquasar SS 433 (Dubner et al.,1998), which has similar energeticrequirements to the IC 342 X-1 nebula.Finally, it is possible that the entirenebula could be X-ray ionised. Pakull& Mirioni (2003b) suggest that XINshould contain an extended warmlow-ionisation region with strongcharacteristic lines such as [SII], whichwould mimic a SNR spectrum.

Acknowledgments

We thank the WHT/INTEGRAL teamfor their assistance in the planning andimplementation of our programme,and for the use of their data reductionroutines. TPR is grateful to PPARC

for financial support in the form of aPDRA at the University of Leicester.¤

References:

Begelman M. C., 2002, ApJ, 568, L97.

Cioffi D. F., McKee C. F., Bertschinger E.,1988, ApJ, 334, 252.

Colbert E. J. M., Mushotzky R. F., 1999,ApJ, 519, 89.

Dubner G. M., Holdaway M., Goss W. M.,Mirabel I. F., 1998, AJ, 116, 1842.

Goad M. R., Roberts T. P., Knigge C., LiraP., 2002, MNRAS, 335, L67.

King A., Davies M. B., Ward M. J., FabbianoG., Elvis M., 2001, ApJ, 552, L109.

Makishima K. et al., 2000, ApJ, 535, 632.

Matonick D. M., Fesen R. A., 1997, ApJS,112, 49.

Pakull M. W., Angebault L. P., 1986, Nature,322, 511.

Pakull M. W., Mirioni L., 2003a, inProceedings of the Symposium “NewVisions of the Universe in the XMM-Newton and Chandra era”, ed. F.Jansen, ESA SP-488 [astro-ph/0202488].

Pakull M. W., Mirioni L., 2003b, RMxAC,15, 197.

Roberts T. P., Goad M. R., Ward M. J.,Warwick R. S., O’Brien P. T., Lira P.,Hands A. D. P., 2001, MNRAS, 325, L7.

Roberts T. P., Goad M. R., Ward M. J.,Warwick R. S., 2003, MNRAS, 342, 709.

Tim Roberts ([email protected])

Figure 2. The unusual ionization structure of the IC342 X-1 SNR. The three coloursshow 5300–5500 Å continuum emission (green), continuum-subtracted Hα +[NII]emission (red), and continuum-subtracted [OIII] (blue, highlighted by contours). Theuncertainty in the position of IC342 X-1 is again shown by the circle.

Radius (for d = 3.9 Mpc): Rneb=55 pcShell velocity: Vs <180 km s-1

Age: τneb >92,000 yrInitial energy (×1051 erg): E51>2Ambient ISM density: n0 >0.12 cm-3

Electron density: Ne <40 cm-3

Electron temperature: Te<3×104K

Table 1. The properties of the SNR.

[OIII] Nebulosity

A second remarkable feature of thisnebula is demonstrated in Figure 2.The morphology of its [OIII] emissionis distinctly different to the otheremission-lines, appearing to sit in twopatches on the inside of the largernebula. Importantly, the [O III]recombination time for the inner edgeof the nebula is far less than its age,implying that a process other than thesupernova blast wave must haveenergised the [O III] emission. Onepossibility is that the excitationoriginates in the high-energy emissionof the ULX. Unfortunately ourobservation is not sensitive to theHeII λ4686 line, the classic signatureof an X-ray Ionised Nebula (XIN;Pakull & Angebault, 1986). However,calculations show that the ULX canproduce a photoionizing flux sufficientto excite at least the inner regions ofthe SNR shell. If the excitation is dueto the ULX, then its morphologystrongly suggests that the X-rayemission of the ULX is anisotropic,consistent with the beamed X-raybinary models of King et al. (2001).

A Hypernova Remnant?

The location of a probable black holeX-ray binary within an unusuallyenergetic supernova remnant appearsto satisfy the conditions for ahypernova remnant, i.e., the aftermathof a gamma-ray burst in which amassive star has collapsed to a blackhole triggering a very energeticsupernova explosion. If so, thisobservation provides direct evidence


1 1

P lanetary nebulae (PNe), thefate of the vast majority of starswith a mass similar to the Sun

or a few times higher, represent a shortbut well characterised stage of stellarevolution. It is the time at which starsexperiment their last thermonuclearburning on the surface of a core thathas been left naked by strong massloss during the previous red giantphase. The combination of a hotluminous star (up to 500,000 K andmore than 10,000 solar luminosities)and a low density expanding wind,allows the formation of an extremelyluminous nebula that reprocesses theenergetic continuum radiation from thestellar nucleus into specific emission-line spectra from atomic ionised gas.This makes PNe easily observable inour own galaxy (being among thepreferred targets for amateurtelescopes), but equally well detectablein external galaxies even withrelatively small telescopes.

The technique used for searching PNein external galaxies is almostinvariably that of obtaining a narrow-band, continuum-subtracted image ina filter isolating the forbidden emissionat 5007Å from double-ionised atomicoxygen [OIII]. A large fraction of thetotal luminosity of the star is in factconcentrated in this line, and this isthe unique property that makesindividual stars in the planetary nebulaphase visible to very large distances:up to several hundred solarluminosities can be emitted in a singleand very narrow spectral line !Observation of the hydrogen Hα line,also very bright, is sometimes addedto discriminate against the detectionof highly redshifted galaxies (e.g. [OII]emitting galaxies at redshift z= 0.34,which shifts the O+ emission to therest wavelength of [OIII]λ5007, orLyman-α emitters at redshift 3.1), orto estimate the ionisation class anddiscuss possible contamination bycompact HII regions. Another basic

criterium to select candidateextragalactic PNe is that they are notspatially resolved by ground basedimaging, their sizes being usually afraction of a parsec which translatesinto a couple of hundredth of an arcsecat a distance of 1Mpc, approximatelythe outer edge of the Local Group.

PNe in external galaxies provide a toolto investigate some importantastrophysical problems. First of all,their number reflects the total massof the underlying stellar populationfrom which they derive. In fact, oneof the most robust predictions of stellarevolution theories allows us to relatethe number of objects nj in any postmain-sequence evolutionary phase tothe lifetime of that specific phase, inthe hypothesis of a population of coeval,chemically homogeneous stars (Renzini& Buzzoni, 1986). The relation is assimple as this:

integrated stellar light is low andhardly detectable, like the intergalacticand intracluster space and in the haloesof elliptical galaxies (Arnaboldi etal., 2002).

Extragalactic PNe also provideimportant information on the chemicalevolution of the host galaxies, as thenebular abundances of elements likeoxygen, neon, sulphur, or argon, donot vary significantly during theevolution of low-mass stars (i.e. theyare not significantly produced ordestroyed). Therefore the abundancesof these elements probe the initialmetallicity of their environment at thetime when their progenitors were born.This covers a range in ages that canbe hardly covered using other classesof stars.

Moreover, nowadays PNe are used asreliable extragalactic distanceindicators, through the invariance oftheir luminosity function with galaxiantype and metallicity (Jacoby, 1989).Finally, as they are also detected instellar systems of low surfacebrightness, they are extremely valuabletest particles to map the dynamics ofstars in galaxies up to very largegalactocentric distances (the PlanetaryNebula Spectrograph at the WHT isan instrument especially built forthis purpose, see e.g. Merrifield etal. (2001).

For the reasons above, we have beenintensively searching for PNe in nearbygalaxies as one of the main objectivesof the Local Group Census (LGC). TheLGC is a narrow-band survey of thegalaxies of the Local Group observablefrom La Palma, that was awardedobserving time during period two ofthe ING Wide Field Imaging Surveyprogramme (http://www.ing.iac.es//WFS/). Observations are being obtainedwith the Wide Field Camera at the2.5m Isaac Newton telescope, coveringa field of view of 34′× 34′. The aim of

The Census of Planetary Nebulae in the Local Group

Romano L. M. Corradi (ING), Laura Magrini (University of Firenze, Italy), Pierre Leisy (ING/IAC),Colin Davenport (ING)

nj=ξ ⋅ LT ⋅ t j ,•

where ξ is the so-called specificevolutionary flux (number of stars perunit luminosity leaving the mainsequence each year), LT is the totalluminosity of the galaxy, and tj theduration of the evolutionary phase j(≤ 10,000 yrs for the PN phase). Notethat ξ is only slightly dependent on theage of the stellar population, its initialmass function and metallicity. Thuscounting PNe implies measuring thetotal mass of the parent stellarpopulation. Once the masses of theprogenitors of the PNe are estimated,it also allows us to discuss the starformation history of the host galaxyfor the range of ages covered by thePN progenitors, roughly 1 to 10 Gyr(it is still not clear which is the lowermass limit for forming a planetarynebula). In particular, PNe have provento be excellent tracers of stellarpopulations in large volumes with arelatively low density of stars, whose

•

•


1 2

the survey is to find, catalogue andstudy old and young emission-linepopulations (e.g. HII regions, PNe, SNremnants, Luminous Blue Variables,WR stars, symbiotic binaries, etc.) tounprecedented levels. The value ofnarrow band [OIII], Hα, [SII], and HeIIimages is enhanced with complementarybroad band data (g, r, i). This enables,in principle, the linkages betweenstellar populations to be probed.

The first part of the analysis of oursurvey data has been focused on thesearch for PNe in dwarf irregulargalaxies of the Local Group. We areespecially interested in these objects asdwarf galaxies are the most numerousgalaxies in the nearby Universe.According to the hierarchical scenariosof galaxies formation, dwarf galaxiesare the first structures to form andfrom their merging, larger galaxies arebuilt. The Local Group, which appearsto the rest of the Universe as anordinary collection of dwarf galaxies(90% of its 40 known members)dominated by two main spiral galaxies,is an ideal laboratory as the low-luminosity dwarf galaxies can bestudied in detail.

Before our census, only a small numberof PNe were known in the dwarfirregular galaxies of the Local Group(3 in Sagittarius, Walsh et al., 1997;Dudziak et al., 2000; one in Fornax,Danziger et al., 1978; one in Leo Aand another one in Sextans A, Jacoby& Lesser, 1981; one in NGC 6822,Killen & Dufour, 1982). With oursurvey, so far 16 PNe in IC 10, 5 inSextans B and 3 in IC 1613 were newlydiscovered, while the existence of onecandidate planetary nebula in Leo A,one in Sextans A, and about 25 inNGC 6822 were confirmed (Magriniet al., 2002, 2003; Leisy et al., 2003).No PNe are instead found in GR8, asexpected because of the smallluminosity of this galaxy. The dataare illustrated in the colour figures inthe next page; in each image, green isthe [OIII] emission, red the Hα one,while blue corresponds to the broadband Sloan-g images, mainlydominated by continuum stellaremission. In these images, planetarynebulae stand out as green or yellowdots (a striking example is the green

luminous object on the upper-left sideof the image of Leo A).

The LGC detections provide a morecomplete view of the population of PNein the Local Group. These new dataappear to be consistent with thepredictions of the stellar evolutiontheories mentioned above, as thenumber of observed PNe in each galaxyscales reasonably well with theluminosity of the galaxy (Magrini etal., 2003). In spite of this agreement,there are also some interestingpeculiarities. For instance, Sextans Aand Sextans B have very similarV -band luminosities and mass, butwhile five PNe were discovered inSextans B, only one candidate isdetected in Sextans A. Statistically, thisdifference is only marginallysignificant, but may suggest somedifferences in their star formationhistory, as evidenced by the strongermain-sequence population of Sextans Acompared to Sextans B.

We have also investigated thebehaviour of the numbers of planetarynebulae with galaxy metallicity, andfound a possible lack of PN when[Fe /H]<< –1.0, which might indicatethat below this point the formation rateof PNe is much lower than for stellarpopulations of near solar abundances.This might in turn be related to themass loss mechanism in evolved red-giants, that is governed by radiationpressure on dust grains, and istherefore sensitive to a significantdeficiency of heavy elements in thestellar atmosphere.

Another result of our survey is thediscovery of candidate planetarynebulae at large galactocentricdistances, like in the case of IC 10where they cover an area of 3.6×2.7kpc,much more extended than the25 mag ⋅arcsec–2 diameter (1.1×1.3 kpc).Are these PNe related to the enormousneutral hydrogen envelope surroundingIC10 (Huchtmeier, 1979)?

The new detections of the LGC areclearly a starting point for futurespectroscopical studies of individualobjects, aimed at confirming theirnature as PNe and, more importantly,at determining their physical and

chemical properties and of their hostgalaxies. This will be our next objective,together with the analysis of the othergalaxies observed by the LGC.

Updated information on the status ofthe project, including the list of all theastronomers and institutions involved,can be found at:http://www.ing.iac.es/~rcorradi/LGC/.

¤

References:

Arnaboldi, M., Aguerri, J. A. L., Napolitano,N. R., Gerhard, O., Freeman, K. C.,Feldmeier, J., Capaccioli, M., Kudritzki,R. P., Mendez, R. H., 2002, AJ, 123, 760.

Danziger, I. J., Webster, B. L., Dopita, M. A.,Hawarden, T. G., 1978, ApJ, 220, 458.

Dudziak, G., Péquignot, D., Zijlstra, A. A.,Walsh, J. R., 2000, A&A, 363, 717.

Huchtmeier, W. K., 1979, A&A, 75, 170.

Jacoby, G. H., 1989, ApJ, 339, 39.

Jacoby, G. H., Lesser, M. P., 1981, AJ, 86,185.

Killen, R. M., Dufour, R. J., 1982, PASP,94, 444.

Leisy et al., 2003, in preparation.

Magrini, L., Corradi, R. L. M., Walton, N.A., Zijlstra, A. A., Pollacco, D. L., Walsh,J. R., Perinotto, M., Lennon, D. J.,Greimel, R., 2002, A&A, 386, 869.

Magrini, L., Corradi, R. L. M., Greimel, R.,Leisy, P., Lennon, D. J., Mampaso, A.,Perinotto, M., Pollacco, D. L., Walsh, J.R., Walton, N. A., Zijlstra, A. A., 2003,A&A, 407, 51.

Merrifield et al., 2001, ING Newsl., 5, 17.

Renzini, A., Buzzoni, A., 1986, in SpectralEvolution of Galaxies, eds. Chiosi, C. &Renzini, A., Reidel, Ap. Space Sci. Lib.,122, 195.

Walsh, J. R., Dudziak, G., Minniti, D.,Zijlstra, A. A., 1997, ApJ, 487, 651.

Romano Corradi ([email protected])

Next page: Three-colour images ofNGC6822, IC1613, IC10, Leo A, GR8,

Sextans B, Sextans A and WLM galaxiesof the Local Group. In each image, green

is the [OIII] emission, red the Hα one,while blue corresponds to the broad band

Sloan-g images, mainly dominated bycontinuum stellar emission. In these

images, planetary nebulae stand out asgreen or yellow dots (a striking example

is the green luminous object on theupper-left side of the image of Leo A).

NGC 6822

IC 1613

GR 8

IC 10

Leo A

Sextans A

Sextans B

WLM


1 5

simulator, please consult our website at: http://www.iac.es/proyect/LIRIS/.LIRIS is equipped with a 1024 ×1024Hawaii detector, using a SDSUcontroller. The engineering detectorwas used during the commissioning.The detector temperature was keptstable at 61K. The readout noise was4.8ADU or 24e– in double correlatedmode. This value can be effectivelyreduced using multiple non-destructivereadouts (for instance it reduces to12e– when 4 readouts are made). Theminimum integration time allowedby the controller is 1s. LIRIS is alwayslimited by background noise forimaging mode in H and Ks bands,and in J band for exposures longerthan 4.5s. In spectroscopic mode thesame condition is reached for exposuretimes longer than 380s and 42s in theranges Z – J and H – K, respectively.

The photometric zero point and thesystem efficiency (optics & detector)were measured in the different bands(see Table 1). We also report theaverage sky brightness. Remarkably,the sky background in Ks measuredwith LIRIS is among the lowestreported with similar instrumentationat different telescopes. We would liketo point out the fact that the WHT isnot an IR optimised telescope. Thelimiting magnitude was computed fordetection at 3σ in an hour of on-sourceintegration with a seeing of 0.7″.

TELESCOPES AND INSTRUMENTATION

First Commissioning of the IR Spectrograph LIRIS

J. A. Acosta Pulido, E. Ballesteros, M. Barreto, R. Barreto, E. Cadavid, J. Carrillo, S. Correa,J. M. Delgado, C. Domínguez-Tagle, E. Hernández, R. López, A. Manescau, A. Manchado,H. Moreno, J. Olives, L. Peraza, F. Prada, P. Redondo, V. Sánchez, N. Sosa, F. Tenegi (IAC)

T he near-infrared spectrographLIRIS was first commissionedon the WHT on the nights of

15–19 Feb 2003. During all that timethe instrument functioned with nomajor failures. At the time ofcommissioning LIRIS included imagingand spectroscopic observing modes.Spectroscopy could be done at lowresolution (about 700 using thenarrowest slit of 0.65″) using twogrisms: One simultaneously coversthe bands Z and J (9230–15,425Å)with a dispersion of 6.1Å/pix; and theother covers the bands H and K(14,600–24,946Å) with a dispersionof 10Å/pix.

The weather conditions during thecommissioning were good; 3 out of 4nights were photometric and only halfa night was lost due to high humidity.On two of the nights the seeing wasabout 0.5″, as measured by LIRIS. Theimage quality over the whole fieldappeared to be very good (see Figure 2).The PSF over the whole field remainedvery uniform, with variations of widthsmaller than half a pixel (0.13″) acrossthe whole field of view. The imagequality was very good in the differentbands, and the best telescope focusresults constant, independent of thefilter used.

LIRIS was funded and built by the IAC,the optical and the conceptualmechanical designs were providedunder contract by the UKATC. TheSpanish contractor INGOVImanufactured the LIRIS vacuum vesseland optical bench. For more detailedinformation about LIRIS’ design,manufacturing and capabilities seeAcosta-Pulido et al. (2002, INGNewsletter, 6, 22). For updatedinformation, including instrument

Figure 1 (top left). LIRIS mounted on theWHT Cassegrain focus. LIRIS cryostatcan be seen at the bottom of thetelescope focus, with the two electronicsracks at both sides. Figure 2 (top right).The globular cluster M5 in the J band.The FWHM of the PSF was 2 pixelscorresponding to 0.5 ″. The image qualityis very good over the whole field of view(4.2arcmin2). Figure 3 (right). Arrival ofLIRIS at the WHT in January.

Filter J H Ks

Zero Point 24.83 25.17 24.55Efficiency 0.34 0.53 0.52m lim 23.4 22.4 21.8<msky/arcsec2> 15.4 14.2 13.0

Table 1. LIRIS photometric characteristics.


1 6

The instrument has so far been usedto observe several astrophysical targetsof interest. Some of the initial resultsare presented in the accompanyingfigures (see Figures 4, 5 and 6). Oneof the most remarkable results wasthe observation of the most distantquasar known at the time (SDSSJ1148+5251, z= 6.41). A spectrum inthe bands Z and J was obtained, inwhich several broad features weredetected.

We would like to thank all ING staffand the IAC Instrumentation Areafor their excellent support during thepreparation and commissioningperiods.¤

José Acosta ([email protected])

The rigidity of the instrument, inparticular the flexures of the slit wheelwith respect to the rest of optics is acritical point for spectroscopicobservations. A displacement along thespectral axis during a LIRIS exposurewill introduce several unwantedeffects, such as smearing of thespectral features, and flux losses dueto light coming from the object notpassing through the slit. Moreoverthe position of the slit on the detectorneeds to be known at any time inorder to accurately centre the targetobject. The LIRIS rigidity was checkedwith good results. It was found thatthe maximum shift (with respect tozenith position) along the spectraldirection does not exceed 0.5 pixel, or0.12″, at 45º zenith distance (ZD),although it reaches 0.8 pixel at 60º ZD.The flexures along the spatial directionwere slightly worse, reaching about1pixel (0.25″) at 45º ZD and certainrotation angles of the Cassegrainturnplate.

A key issue in near-IR astronomy isthe sky background subtraction. Thisis generally performed by followingdithering patterns on the sky, whichinvolves a good deal of interaction ofthe instrument data acquisition withthe telescope. The WHT was alreadyprepared for this based on the INGRIDexperience, although the instrumentLIRIS introduces new demands in thespectroscopic mode. For IR spectroscopythe target is often offset along a narrowslit and should be always maintained

well centred on it to avoid flux losses.For this purpose the telescope and theauto-guider should work insynchronisation with the instrumentdata acquisition. It was found thatthe repeatability of the offsets couldnot be guaranteed beyond 1pixel or0.25″, which involved target re-centringafter a couple of movements. Howeverthe WHT auto-guider is going to bechanged and the situation shouldimprove.

The next commissioning period isforeseen for February 2004. Duringthat period the multi-objectspectroscopy mode will be the mainfocus. We also expect that LIRIS canprovide polarimetric and coronographiccapabilities.

Figure 4 (left). The planetary nebula NGC2346 in the emission of H2 ν =1-0 S(1) at 2.122µm. The field of view covered in thispicture is approximately 3.2x 2.8 arcmin2. North is to the right and East is at the top. Note the clumpy structure in the lobes andthe bright central star, only visible in the infrared. Figure 5 (right). The Seyfert 2 galaxy NGC4388 observed in the J filter. The fieldof view covered in this picture is 2.5x2 arcmin2. North is at the top and east to the left. Note the very bright active nucleus andthe patchy structure of the spiral arms, revealing the presence of obscuring dust lanes.

Figure 6. Two-dimensional spectrum of the most distant QSO at z=6.41 (top brightrow). The extracted spectrum is shown in the left panel. A fit to the spectrum is alsoshown, where several broad emission lines are identified. The most intense feature isthe CIV line, detected with a S/N ratio of 10. The spectrum is the co-addition of 5frames of 850s exposure time each, giving an approximate total time of 70 minutes.


1 7

I n May 2002 the adaptive opticssystem NAOMI on the WHTreceived an instrument upgrade:

the coronographic mask device OSCA(Optimized Stellar Coronograph forAdaptive optics).

Coronography in astronomy intendsto overcome huge brightness differenceson small spatial scales — meaninghigh contrast imaging. Thus the mainscience driver for coronography is theinvestigation of the close enviromentof bright stellar objects, e.g. lookingfor faint companions or dusty material.

Seeing limited imaging techniquescan only provide poor contrast ratiosbetween the peak of the point spreadfunction (PSF) and its wings.Employing adaptive optics (AO)techniques allows for diffraction limitedimages to be obtained in which thedetectivity of faint objects /structuresclose to bright objects is greatlyimproved. It is important to note thateven using AO the form of the PSFstill contains a halo the size of theseeing disk on which the diffractionlimited core is located. Adaptiveoptics is best suited for coronographyas the amount of suppressionachievable with a coronograph dependsdirectly on the image quality (e.g.FWHM and Strehl ratio).

The coronograph OSCA has beendesigned and built at UniversityCollege London by a team led by P.Doel. Here we give only a briefoverview over the optical system ofOSCA. For further details, please referto the paper by Thompson et al. (2003).OSCA is permantly mounted on theoptical bench of NAOMI. To deploy itinto the light path a pneumatic systemlifts OSCA from its parking positioninto the light beam (see Figure 1). Oncein the lightpath, a mirror (a) picks upthe converging beam coming from

NAOMI and directs it onto the focalplane masks (b) and then onto thefirst off axis paraboloid (c). Currentlysix hard edged masks with sizesbetween 0.25″ and 2.0″ are installed.These masks are not fully opaque thusenabling good centering of the targetbehind them and also allowing goodastrometry to be obtained as the lightcentre of the target can be wellmeasured. In addition to these masks,two gaussian shaped masks withFWHM=0.5″ and 0.6″ for opticalwavelengths, have been available sinceearly 2003. All masks are depositedonto wedged substrates giving acircular field of view of approximatly20″ in diameter. After passing aLyotstop (c) the beam leaves OSCA viaan optical system (d) which conservesthe focal point and f-ratio of the

NAOMI beam. Therefore OSCA canbe used with any instrument fed bythe AO system.

First on-sky tests show that OSCAallows contrast ratios to be overcomeof about ∆H~8 mag compared to thepeak intensity over a distance of 2″ ora suppression of about 0.5 –1 magcompared to the non-coronographicimage. This is comparable to othercoronographic systems on 4m classtelescopes using AO systems. As OSCAis not a cooled coronograph it will notbe used at wavelengths longer thanH-band which is also the currentlimitation of INGRID used withNAOMI. Also, as OSCA is part of theNAOMI system the same restrictionsapply for OSCA as for NAOMIobservations. For details see the

OSCA — The Coronographic Mask Device for NAOMI

S. G. Els1, S. Thompson2, P. Doel2, P. Jolley1, C. Benn1, M. Blanken1, T. Gregory1, R. Østensen1,F. Prada1, I. Soechting1

1: Isaac Newton Group; 2: University College London

Figure 1. Photograph of OSCA from above the NAOMI bench. The light path isindicated by the arrows. The dashed red line shows the lightpath without OSCA. Thepink letters indicate the OSCA optical components and are described in the text.


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NAOMI webpage:http://www.ing.iac.es/Astronomy//instruments/naomi/index.html

With OSCA, ING now offers to itsusers a coronographic device inconjunction with its adaptive opticssystem NAOMI. At present it can beonly used for near infrared imagingusing ING’s infrared camera INGRID.Observers interested in using OSCAcan apply for time in the same wayas for other instruments at ING.

With its move to the new temperaturecontrolled Nasmyth station – GRACE– in early 2003 ING’s adaptive opticsfacility NAOMI is expected to performbetter and with greater stability inthe near future, positively influencingcoronographic work.

ING is going to also offer a uniquefacility to combine AO-fed integral fieldspectroscopy with coronography. A newinstrument for the adaptive opticssystem will be the integral-field-spectrograph OASIS, installed andcommissioned during summer 2003.OASIS will receive an AO correctedinput beam from NAOMI. OSCA canthen be operated as a NIR imagingcoronograph but as well as in thefollowing instrument combination:NAOMI+OSCA+OASIS.

Updated OSCA informations areprovided on its webpage:http://www.ing.iac.es/Astronomy/

/instruments/osca/index.html.¤

References:

Thompson, S., Doel, P., Bingham, R., etal., 2003, SPIE Proc, 4839, 1085.

Sebastian Els ([email protected])

Figure 2 (left). Example of a star behindthe 2″ coronographic mask. As the maskis not fully opaque the stars light peak canstill be seen and indicates in this case thatthe star is not perfectly centered behindthe mask. Figure 3 (right). Suppressiontest of OSCA. The upper line indicates aradial cut of a star without OSCA in theNAOMI beam. The relatively low signalto noise of that cut is due to the shortintegration time of that image. The lowerline shows a radial cut through acoronographic image taken with OSCA.

O n the nights of November 7thto 10th, a team from theUniversity of Durham

Astronomical Instrumentation Group,together with colleagues from MPIAHeidelberg, had a highly successfulsecond run with the prototype laserguide star on the WHT. Representingthe completion of Phase B of theDurham experimental RayleighLaser Guide Star (LGS) programme,the two teams were able to collectsimultaneous natural and laser guidestar wavefront data.

3.5W of 523 nm laser light wasprojected onto the sky using a custom-made 30cm launch telescope mountedbehind WHT secondary. The laseritself was installed in GRACE and thebeam relayed to the launch telescopevia enclosed fold mirrors attached tothe WHT structure.

A novel, focus-insensitive, wavefrontsensor was utilised by the MPIA teamto observe the LGS return in GHRIL.Early analysis of the collected dataindicates that the focussed spot sizeat 4.5 km was approximately 2 ×4arcseconds in seeing of 1 arcsecond, thespot elongation being due to theellipticity of the laser output itself.

Reduction of the collected data isunderway. The laser operated reliablyover the 3.5 nights with no technicaldowntime. This development work

Rayleigh Laser Guide Star Returns tothe WHT

Tim Morris (Durham Univ.)

Figure 1 (top). The laser launchcoincided with a Lunar eclipse. Figure 2(middle). Laser launch telescope mountedat the top of the WHT, behind the telescopesecondary mirror. Figure 3 (bottom). Thelaser beam seen projected against thenight sky above the WHT.

indicates that the proposed 20Wcommon-user Rayleigh laser guide starsystem for NAOMI can be implementedwith confidence.

The assistance and support providedby ING, without which the trial wouldnot have been possible, is gratefullyacknowledged.¤

Tim Morris ([email protected])


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A new method for measuring thealtitude and velocity ofturbulent layers in the

atmosphere —which cause theastronomical seeing and scintillation or‘twinkling’ of the stars— has beendemonstrated at the WHT. SLODAR(SLOpe Detection And Ranging) is atriangulation method, in which theturbulence profile is recovered fromobservations of bright binary starsusing a Shack-Hartmann wavefrontsensor.

In the past, astronomers have beenconcerned only with the overall effectsof the turbulence, in terms of theresulting image spread or ‘seeing angle’(FWHM for a point source) at thetelescope focus. However with theadvent of adaptive optical correctionfor astronomy, measurements of thechanging atmospheric turbulencestructure are of increasing importance.

The altitude distribution of theturbulence determines the correctedor ‘isoplanatic’ field of view foradaptive optics (AO). High altitudelayers reduce the isoplanatic angle,since for these layers the wave-frontaberrations measured in the directionof the AO guide star will not coincideperfectly with the aberrations at off-axis field-angles.

The velocities of the turbulent layersare also important, since thesedetermine the rate of change of theseeing aberration at the telescope, andhence the temporal bandwidth of theAO control system required to achieveeffective image correction.

SLODAR is a highly automated systemwhich can provide real-time data foroptimising and calibrating observationswith AO. More details of the methodand instrument can be found at theDurham astronomical instrumentationwebsite: http://aig-www.dur.ac.uk//fix/projects/slodar/res/wht.html.

Figures 1 and 2 show SLODAR resultsfor April 15th and 16th, both recordedin excellent seeing (0.45 arcsec), butwith contrasting turbulence profiles.The conditions on April 15th weredominated by ground-level turbulence,whereas significant turbulence athigher altitudes was present on the16th. Hence although the overallseeing was the same for the two nightsthe conditions for AO were different.The isoplanatic angle was very largeon April 15th, but was reduced onthe 16th by the presence of the highaltitude turbulence.¤

Richard Wilson ([email protected])

SLODAR: Profiling Atmospheric Turbulence at the WHT

Richard Wilson, Christopher Saunter (University of Durham)

Figure 2. Snapshot of the WHT SLODARsystem graphical user interface, showingthe Shack-Hartmann spot patterns for abinary star, and real-time plots of theturbulence-altitude profile and theintegrated turbulence strength versus time.

Figure 1. Normalised profiles of thestrength of optical turbulence versusaltitude for April 15 21:38 UT (top) andApril 16 20:45 UT (bottom), 2003.

T he profile of the WilliamHerschel Telescope (WHT) haschanged since the beginning

of this year, with the addition of a newfacility at one of the telescope’sNasmyth platforms. For many yearsthe WHT has had the GHRIL buildingon the Nasmyth1 platform — now theING has added GRACE to the opposite

Amazing GRACE

G. Talbot, A. Chopping, K. Dee, D. Gray, P. Jolley (ING)

side of the telescope. GRACE(GRound based Adaptive opticsControlled Environment) is a dedicatedstructure designed to facilitate theroutine use of adaptive optics (AO) atthe WHT, using ING’s AO instrumentsuite. The design of GRACE allows forthe future use of laser guide stars.


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Top left: NAOMI suspended from the crane (by the yellow straps) above GRACE, justbefore being lowered through the access hatch. Middle top: The Eagle has landed!The NAOMI bench complete with deformable mirror being lowered onto its kinematicmounts inside GRACE. Right top: Dr Ronald Stark, Dr Annejet Meijler and Dr RenéRutten standing up in front of WHT. GRACE can be seen on the Nasmyth platform onthe left, opposite to GHRIL. Middle left: Inside GRACE. Bottom left: Inauguratingcommittee leaving GRACE. Bottom middle: Dr Annejet Meijler uncovering theinauguration plate. Bottom right: Dedication to ING staff.

The AO suite consists of the AO systemNAOMI, the coronograph OSCA, nearIR imager INGRID and the opticalintegral field spectrograph OASIS. Thebench-mounted NAOMI systemachieved first light in 2000 withINGRID as its science camera inGHRIL, but until the advent ofGRACE, the NAOMI optical benchcomplete with delicate (and expensive!)optical and electronics components hashad to be craned in and out of GHRILevery time there has been aninstrument change. Quite apart fromthe risk involved, there has been amassive overhead for ING staff indisconnecting and removingeverything, with an even more massiveoverhead in putting everything back,aligning it and getting it working —three weeks was allowed for this !

After the first NAOMI instrumentchange, it was realised that for routineoperation moving NAOMI about wasnot sustainable. This was re-inforcedwith the signing of the agreement withthe Centre de Recherche Astronomiquede Lyon (CRAL) to bring OASIS to theWHT, which added a further largecomplex instrument to the equation.

Accordingly ING made the decision tocreate a dedicated facility on theNasmyth2 platform then used by theUtrecht Echelle Spectrograph (UES).A suitable building was designedtaking into account the requirementsof the AO suite. To provide sufficientspace an extension to the Nasmythplatform was needed and this was alsodesigned at this time. A local La Palmacompany, Grolei Servicios S. L., wassuccessful in winning the contact toconstruct the building. Their proximityto ING allowed progress to bemonitored, problems resolved andmodifications to be made quicklyresulting in an excellent building,fulfilling ING’s requirements.

GRACE is not just a building, it offersall of the systems associated withproviding the controlled environmentnecessary, especially cooling andfiltering of the air, together with allof the services needed includingelectrical supplies, lighting and acomputer network. While the building

was being built, we continued to designand specify these systems.

Crucial to success is environmentalcontrol. The GRACE electronics roomis maintained at a constanttemperature by an air-handling unitmounted on the roof. For the opticsroom, the air is again maintained ata constant temperature for the stabilityof the instruments, additionally beingfinely filtered and introduced at lowvelocity through laminar flow units tominimise air currents. The heat fromGRACE is removed (not dumped in thedome) through a water glycol circuit.The opportunity was taken to upgradethe cooling capacity to the whole ofthe WHT, in order to meet future needsincluding a laser guide star, by buyingand installing a new external plant.

The first step was the removal of UESand the extension and modification ofthe platform ready for the building.

Installation of the completed building,which was dismantled fortransportation, began late in 2002. Asignificant moment was reached on18 March 2003 when the NAOMIadaptive optics system on its benchwas lifted into its new and permanenthome. This was followed quickly byits first light in GRACE using INGRIDon 13 April at the beginning of anine-night run. The second ‘first light’event for GRACE followed soon afterwhen, on the 11 July, OASIS went onsky with NAOMI on its firstcommissioning night.

A key concern was that GRACE wouldnot change the telescope performance


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when replacing UES. During theconstruction phase several blocks(weighing a tonne each) were used toensure that the removal of UES didnot unbalance the telescope. Thesewere progressively removed as GRACEwas assembled. The opportunity wastaken to brace the new platformextension to the telescope structure.Tests after GRACE installation wascomplete show this was effective inraising the natural frequencyconsiderably, away from the telescope’s

azimuth locked rotor frequency, whichwas the required result.

During the time of restructuring forING, the creation of GRACE is amajor achievement, especially whenset against the background of otherproject work not least adding theUniversal Science Port to NAOMI tofeed OASIS. Many, if not most INGstaff have contributed to GRACE andin getting the AO suite installed andworking. In the end —over the lastmonths, then weeks— it’s still hard

to believe how much was done andhow hard everyone worked.

Dr Annejet Meijler, the Director of theCouncil of Physical Sciences of theNWO, formally inaugurated GRACE onMay 2nd, 2003. ING staff take pridein having a world class environmentfor AO which was, in the words of theplaque unveiled, ‘conceived, designedand built’ by them.¤

Gordon Talbot ([email protected])

T he optical integral-fieldspectrograph OASIS, formerlyat the CFHT, has moved

permanently to the WHT. It is nowinstalled at one of the science ports ofNAOMI, the WHT’s adaptive-opticssystem. OASIS was successfullycommissioned on-sky with NAOMI inJuly 2003, and it is offered to thecommunity on a shared-risks basis insemester 2004A.

OASIS offers a range of spatial andspectral resolutions. An area of skybetween 3 and 16 arcsec in diameter(4 enlarger options) can be imagedonto the array of 1100 lenslets in thefocal plane. Six grisms provide spectralresolutions in the range 1000<ℜ<4000.The 1100 resulting spectra are imagedonto a deep-depletion MIT/LL CCD,with dispersion 1 to 4 Å/pixel (15 µpixels). The CCD has high QE (0.9 at0.75 microns) and low readout noise(2.3 electrons rms in slow mode). Thefringing level is low, ~3% at 0.8 µ, and~10% peak-to-peak at 1µ. A versionof CFHT’s XOASIS data reductionpackage is available at ING forreduction of OASIS data. OASIS canalso be used in imaging mode(primarily for target acquisition), witha field diameter of 38 arcsec. Furtherinformation about OASIS can be foundon the web page: http://www.ing.iac.es/Astronomy/

/instruments/oasis/index.html.

OASIS can be used with or without AOcorrection. NAOMI typically deliversa reduction in FWHM of a few tenthsof an arcsec at wavelengths 0.6–1.0µ.The best corrected seeing achievedduring the July 2003 OASIScommissioning was 0.3 arcsec. Guidestars must currently be brighter thanV ~13. The guide object may also be agalaxy nucleus, if sufficiently compact.Some correction is achieved even whenthe science target lies several 10s ofarcsec from the guide star. Performanceand throughput are expected to be atleast as good as achieved at CFHT.Information about NAOMI can befound on the web page: http://www.ing.iac.es/Astronomy/

/instruments/naomi/index.html. ¤

Chris Benn ([email protected])

OASIS at the WHT

Chris Benn (ING),Gordon Talbot (ING),Roland Bacon (Univ. of Lyon)

Figure 1. OASIS (left) joins NAOMI in the WHT’s new AO-dedicated, temperature-controlled Nasmyth enclosure, GRACE. The IR camera INGRID is visible in theforeground on the right.

Figure 2. OASIS logo for joint operationwith NAOMI.


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A brand new dome stands nearthe William HerschelTelescope, its white surface

reflecting the strong mountainsunshine. Inside is ING’s automaticseeing monitor, RoboDIMM, whichbecame operational in August last year.What was announced as a project inthe March 2001 ING Newsletter, 4, 27,in an article by Thomas Augusteijn,is now a fully functioning reality.

The Differential Image Motion Monitor,proposed by Sarazin and Roddier(1990, A&A, 227, 294) and based on asmall telescope and relativelyinexpensive equipment, has over thelast 10 years become the most commonseeing measurement method used insite testing and characterisation.Nowadays, whether for control ofimage quality or to help decisionmaking in queue scheduling, DIMM-type seeing monitors have become anindispensable tool in observatoriesaround the world. The seeing hasbecome just one more “meteorological”datum that ground-based astronomyis expected to have at its fingertips.

This is why, in common withobservatories in Chile and elsewhere,the ING chose to replace its DIMM(1994–1999) with a new “robotic”DIMM. ING’s RoboDIMM now fulfillsits projected function, which was tomake reliable seeing measurementsavailable throughout the night,requiring user intervention only forstartup and shutdown, and controlledremotely from the WHT control room.

RoboDIMM started observing inAugust 2002, to coincide with the firstNAOMI “science run” at the WHT. Itsampled the seeing on 85 nights untilDecember, missing only 20% of nights,mostly due to poor weather. Aroundthis time, a fault with a telescope drivemotor began causing significant down-time. Now the motor has been replacedand RoboDIMM again accompaniedthe NAOMI run of April 2003. It has

continued in its routine job of seeingmonitoring throughout last summerwithout pause.

Installed atop a 5m tall tower (seeFigure 1), which it inherited from theprevious DIMM installation,RoboDIMM is built out of acombination of off-the-shelf hardwareitems, with the vital addition ofcustom-made software.

The main commercially availablecomponents are a Meade12″ Schmidt-Cassegrain telescope (LX200 model),an ST-5C CCD from Santa BarbaraInstruments (SBIG), and a 12′diameter (3.7 metre) dome withmotorised opening supplied byAstrohaven in Canada. The other vitalcomponent, a mask that goes over thetelescope entrance aperture, wasmachined in-house, to which some

specially ordered small-deviationprisms (‘optical wedges’ ) were added.

It is worth mentioning some specialproperties of the tower, designed byDario Mancini of CapodimonteObservatory and used elsewhere atORM and at ESO’s ParanalObservatory. It consists of a vibration-proof central truss, 5.2m tall, uponwhich the telescope is mounted, anda second tower that surrounds it andsupports an “access platform”. In thecase of RoboDIMM the latter has beenslightly widened to house the dome.The two structures are mechanicallyindependent, so that the telescope isisolated from vibration caused by windbuffeting of the dome. When fully open,the dome presents a 1.5m-high barrierto the wind, from which the telescopestands proud. Since ground layerheating is significantly reduced at theheight of the tower, we assume that

RoboDIMM — The ING’s New Seeing Monitor

Neil O’Mahony (ING)

Figure 1 (left). RoboDIMM stands ready at sunset for a night’s observation at theRoque de Los Muchachos observatory. The dome is opened remotely from theWHT control room and the automatic observing program is started. The tower, 5mtall, is located about 75m north of the dome of the William Herschel Telescope, on agentle slope facing unobstructedly the prevailing winds.

Figure 2 (right). The RoboDIMM telescope at polar park position, with the WHT inthe background. The entrance aperture forms 4 separate images of the same star(the large central aperture is no longer used). The sub-apertures, covered by opticalwedges, are aligned along N/S and E/W (despite what the perspective here maysuggest). Both photos by R. Gorter of Startel.


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the dome induces minimal opticalturbulence and has insignificant effecton the DIMM measurements. Thesupport struts allow the wind to flowaround them, and louvered ports inthe dome floor open automatically,improving vertical airflow.

The control software was written forING by Startel Ltd., in the Netherlands(www.startel.nl (Dutch language),www.robodimm.com (in construction)).It is a C++ program, running on aLinux-based PC, and controls allrelevant automatic functions: fromchoosing suitable targets and acquiringthem, to controlling the CCD,processing measurements and writingthem to a database. The telescope iscommanded through a serial portconnection to the PC, exploiting afeature of the Meade LX200. Theprogram runs a continuous sequence oftasks but also allows user interventionand control of status and data qualitythrough a graphical interface.

Operation

At present the dome must be openedand closed by ING personnel, formallythe WHT Telescope Operator, from thecontrol room of the WHT. This maybe automated in the future, and theupgrade to the telemetry system thatthis would require is being considered.We may then be able to implementautomatic closure in response toadverse weather conditions.

The control program can be leftrunning permanently, because itautomatically stops observing atsunrise and will automatically startagain around the following sunset,depending on the brightness of availabletargets. This lightens the workloadon the TO at the beginning of the nightand helps to provide an early seeingestimate, sometimes even before thesun has gone down! Such an earlyestimate has clear applications inqueue observing. If a seeingmeasurement is available over theprevious 5 minutes, it is published onthe ING Weather Station Web page,(www.ing.iac.es/ds/weather/). Agraph of the night’s data is alsopublicly available (at night time)

through the Weather Page, as is thefull set of archived data (or seehttp://www.ing.iac.es/ds/robodimm/).

The chosen target is the brightestavailable star within 30 degrees of thezenith, in a magnitude range of 2 to 4,although brighter stars can be usedin cloudy conditions. The acquisitionfield is almost 4×3 arc minutes, but ifno star is found in the first CCD imagetaken at the target position, theprogram starts a search spiral. In clearconditions this usually results in asuccessful acquisition within a fewminutes. Once the star is near enoughto the centre of the CCD, the pointingoffset of the telescope is updated, thereadout is windowed and a series of200 images with 10 ms exposure istaken. After this, there is a brief pausewhile the standard deviation of theimages’ relative positions is measuredand the FWHM is calculated from this.The program then repeats the samplingand measurement cycle to providecontinuous monitoring, moving to anew star when the observing elevationgoes below 60 degrees.

A seeing measurement is made atirregular intervals of approximately2.5minutes, and most of that time isspent taking the 200 images in thesample. This is a much longer dutycycle than the original ING DIMM, butit may be possible to speed this up infuture by customising the firmwareon the CCD controller. We estimate afurther 20% of operative time for whichno measurement is available due tomiscellaneous overheads, which maybe improved upon. The software isnow fully functional with smallimprovements continually beingadded, in close collaboration with thesoftware authors, Startel.

Interpretation

RoboDIMM forms 4 images of the samestar (see Figure 2), measuring imagemotion in two orthogonal directionsfrom each of the two pairs of images,from which it derives 4 simultaneousand independent estimates of theseeing. When the system is correctlyset up, these 4 measurements shouldagree, over a reasonably sized sample.

We find that relative sizes vary fromnight to night and show a noticeablesensitivity to the focus position of theMeade telescope, which has beenobserved to flop after a telescope slew.At present the focus has to be adjustedby user command using an electronicfocuser mounted above the CCD, butwe are investigating whether to fixthe focus mechanically or makeautomatic adjustments in the future.

The measurement published on theWeather Page is the average of 4simultaneous database entries, andusers should be aware that this pageis compiled using data from up to 5minutes prior to the posted time. Up-to-date and individual measurementscan be viewed by following the ‘Seeing’link on the Weather Page. Thedatabase values are automaticallycorrected for the observing zenithdistance (dividing by airmass to thepower 3/5) and a wavelength of550nm and the time listed is that atthe middle of the sample. The fourinstantaneous values can differ by,say, 20%, but what matters is thatthere should be no significant longterm difference.

The general impression is that theaverage seeing published on theWeather Page agrees reasonably wellwith seeing being obtained at theWilliam Herschel Telescope, includingNAOMI and Richard Wilson’s“Slodar” wave front sensors (see articleon page 19), and with that obtained atother telescopes. It has shownsensitivity to all seeing conditions,registering averages as low as 0.35″and (during the passing of a warmfront) as high as 7″ ! A comparisonwith seeing data from the IAC DIMM(provided by the Sky Quality Groupat the Instituto de Astrofísica deCanarias), using simultaneous samplesof several hours length from 9 nightsin October 2002, shows a 91%correlation (see Figure 3) between theseeing FWHM measurements madeat the two instruments. The differencesbetween the median values is scatteredaround y = x by an amount varyingbetween 3 and 15% on any given night,or about 8% on average. This averagediscrepancy is no larger than theinternal error of either instrument.


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The good agreement exists in spite ofthe large distance between the twomonitors (several kilometres), the factor10 difference between their sampleduty cycles and their independentdesigns. Periods of rapidly fluctuatingseeing were generally excluded fromthe samples used in this comparison,to avoid possible local effects.

While this result is encouraging andallows a good deal of confidence inRoboDIMM’s seeing measurements, itis not conclusive, since no medianbelow 0.6 arc seconds was used.Calibration of RoboDIMM is ongoing,including characterisation of intrinsicerrors and comparison with otherseeing monitors such as NAOMI’s WaveFront Sensor.

As regards hardware components,ING’s RoboDIMM bears a closeresemblance to the CTIO’s automaticseeing monitor (which, incidentally,is also called RoboDIMM, but theoriginality of that name is disputable!See www.ctio.noao.edu/telescopes//dimm/dimm.html). There is animportant difference in that the CTIO’stakes samples alternating between 5and 10ms exposure time. This formstwo samples from which the imagemotion at “zero seconds exposure” isextrapolated, following the methodestablished by ESO in its Chileanseeing monitors. The zero-secondseeing may reportedly be 10–20%larger than the 10ms estimate (A.Tokovinin, 2002, PASP, 114, 1156),depending on the speed and altitudeof turbulent layers. When comparingresults from different sites, it isimportant to bear instrumentaldifferences in mind but we should alsoremember that the strength of theexposure time “blurring” effect maydiffer greatly between sites, as well asvary over time.

Conclusion

With the commissioning of theRoboDIMM seeing monitor, ING hasprovided its Adaptive Opticsprogramme with an importantauxiliary instrument. It provides aseeing FWHM estimate at regularintervals that can be relied upon to

within about 10% in stable conditions.RoboDIMM allows NAOMIperformance to be monitored in realtime, and also provides essentialinformation for AO observing in queuemode. Additionally RoboDIMMprovides all telescopes on site with datathat can help astronomers to optimally

adjust telescope and instrument focus.It allows them to make sure they arefully availing of the superb naturalseeing available at the Observatoriodel Roque de los Muchachos.¤

Neil O’Mahony ([email protected])

Figure 3. A scatter plot of theseeing FWHM measured bythe IAC DIMM as a function ofsimultaneous RoboDIMMseeing. The best fit line, closeto y=x, and the large correlationcoefficient (0.91) illustrate theclose dependence of thesetwo variables. Each of the 9points represents the medianseeing from simultaneoussamples formed by a continuousperiod of stable seeing lastingseveral hours. The logarithmicscale is necessary to convertseeing FWHM into anapproximately normallydistributed variable.

I t has been a long-standing wishat the observatory to have anight-time all-sky cloud monitor.

A cloud monitor, in the first place,allows astronomers in the control roomto assess the actual situation of thenight sky without the need of havingto rush out for a visual check. Thelatter usually requires rushing up anddown stairs, standing in the coldoutside, and waiting for the eyes to getadapted to the dark, and even then onewould only have a partial snapshot ofthe situation in the sky.

The ideal cloud monitor works atinfrared wavelengths where thecontrast between the cloudless nightsky and the relatively warm clouds ishigh. However, a suitable infraredcamera is rather complex andexpensive to build, and as theequipment has to be located outside,there is a significant maintenance

CONCAM — ING’s All -Sky Camera

René Rutten (ING)

overhead as well. To avoid theseproblems we have been looking for analternative for some time and cameacross CONCAM.

CONCAM stands for CONtinuousCAMera, designed and built by RobertNemiroff and his team at MichiganTechnical University. It is a welldesigned and built, self-containedsystem that only requires connectingto electrical power and the internet.CONCAM consists of a fish-eye lensthat projects the night sky onto anSBIG CCD camera. The camera itselfis controlled by a small notebook PC.The full system sits in a small, well-sealed weather tight box, located on theroof of the liquid nitrogen plantbuilding, close to the junction of theroad leading up to the WHT.

The camera switches itself on duringevening twilight and stops at the end


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L ow Light Level (L3) CCDtechnology is a recentdevelopment from E2V that

opens up interesting new observationalregimes. The technology allowsproduction of scientific CCDs in whichthe read noise of the on-chip amplifierbecomes negligibly low. Additionally,this effective zero-noise performanceis decoupled from readout speeds andthe almost zero noise performanceholds up to frame rates of 1KHz. E2Vachieve this by using an avalanchemultiplication mechanism in thehorizontal register of the CCD. A singlephoto-electron entering this registerexits as a substantial charge packet;the exact gain being variable anddetermined by the level of a highvoltage multiplication clock. At gainlevels of around 500 it becomes possibleto identify individual photon eventsin the image. The downside of L3technology is that the multiplicationprocess degrades the SNR at highersignals by a factor of √ 2. There is alsoa small additional noise contribution

from spuriously generated electronswithin the device.

L3 CCDs should be useful in anyobserving regime currently limited bydetector noise. Wavefront sensing is anobvious application and E2V haveproduced the 128×128 pixel frametransfer CCD60 with this in mind. Wehave purchased one of these and arecurrently working on an upgrade to theNaomi WFS. Figure 1 shows the kindof gains we can expect once this systemis commissioned. For comparison, theperformance of Naomi’s current WFS,the CCD39, is also shown.

Other applications for L3 technologyare currently being evaluated on theWHT using a cryogenic test camera inwhich we have mounted the CCD60(see Figure 2).

This camera was mounted on theAuxiliary port in November where wetested its performance as a fastphotometer. On the 10th we observed

L3 CCD Technology

Simon Tulloch (ING)

—

of the night. Images are taken everycouple of minutes, and exposure timesare up to a few minutes during moon-less periods. Data is automaticallytransferred to Michigan, andimmediately bias corrected and flatfielded. The reduced data and nightlymovies are then made available on theweb through the on-line CONCAMarchive at Michigan (seewww.concam.net). Copies of thereduced (and compressed) nightlymovies are archived locally on LaPalma and available atcatserver.ing.iac.es/weather/

/archive/index.php (follow thelink to the archive and select therequired day).

Currently, CONCAM systems areinstalled not only on La Palma, butalso at Mauna Kea, Kitt Peak, MtWilson, Wise Observatory (Israel),Rosemary Hill (Florida), SouthAfrica and Siding Spring.

The initiative leading to thedevelopment of CONCAM was centredaround the idea of monitoring thebrightness of relatively bright objectsand to permanently look for brighttransient events across the whole sky.Besides these primary goals, CONCAMalso offers very good possibilities forstimulating public interest, as thesequence of CONCAM images veryclearly demonstrate how the sky variesduring nights. CONCAM images canshow a number of interestingatmospheric and night-sky features.CONCAM shows of course the positionof planets and the moon, but also showsthe zodiacal light, it announces sunriseand sunset, and even makes visible thepatterns in the OH night sky lines. Anexcellent set of examples of whatCONCAM sees is shown atwww.concam.net/phenomena.html. ForING, however, the main role it servesis that of all-sky cloud monitor.

The all-sky movies that areautomatically generated give a verygood visual impression of transparencyvariations across the sky, and how itvaries in time. Clouds can be seenrolling in, allowing the astronomer totake advantage of the best parts of thesky and plan the observing programme.Together with the weather maps, the

meteorology data, and the roboticseeing measurements, ING nowpossesses a comprehensive set oftools for planning observations andassessing post-observing data quality.

We are very grateful for the superbcollaboration and assistance receivedfrom the team at Michigan TechnicalUniversity, in particular from RobertNemiroff and David Crook.¤

René Rutten ([email protected])

Top left: CONCAM on the roof of the liquidnitrogen plant. Top right: A closer view ofCONCAM. Above: CONCAM image of thePalmeran night sky.


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the Crab Nebular pulsar and were ableto directly distinguish its 30Hzvariability. The camera used its owndata acquisition system based arounda Linux PC and a slightly modifiedSDSUII controller. This DAS combinedthe functions of an acquisition TV anda science camera. This was importantgiven the rather small 14 arcsec fieldof view. Once the image was acquired,the camera switched to its fastphotometry mode in which it made arapid sequence of 1024 windowedreadouts at a rate of 180 frames persecond. The resultant image formatconsisted of a ‘movie strip’ ofconsecutive frames, a short section ofwhich is shown in Figure 3.

Although faint, the pulsar is visible.The red arrows indicate the frames inwhich the brightness peaks. Ananimated GIF of these pulsarobservations can be found at:http://www.ing.iac.es/~smt/WFS/

/CrabMovie.gif.

Figure 1 (left). Potential L3 gains in NAOMI. Thanks to Richard Wilson for providingFigure 1. Figure 2 (right). The L3 Test Camera.

Figure 3. The Crab Pulsar indicated by the red arrows in this series of frames.

We currently have on order a largerengineering grade L3 CCD measuring512 ×512 pixels. This will beincorporated into a second test cameraand mounted on ISIS where itssuitability for rapid spectroscopy willbe investigated .

Thanks to Durham University’s RLGSteam and to Vik Dhillon for theircooperation in the testing of this newcamera.¤

Simon Tulloch ([email protected])

O ver the last year (2002–2003)ING was subcontracted byUniversity College London

(UCL) to produce a module of 18science fibres for the bHROSinstrument, one of the instruments onthe Gemini South telescope.

bHROS is a high-resolution(ℜ=150,000) prism cross dispersedechelle spectrograph, situated in thepier of Gemini-South. It is fed byoptical fibres mounted on the GMOSinstrument located at the Cassegrainfocus of the telescope. bHROS will havethe highest spectral resolution amongthe optical spectrographs currentlybeing designed and built for 8–10mclass telescopes.

The optical fibre connection betweenGMOS and bHROS consists of 18fibres; 9 fibres with a 120µm corediameter and 9 fibres with a 160µmcore diameter. Both types of fibre hadto be ground and polished at both ends.The GMOS end also had to be mounted

and aligned in an optical assembly (abody plate). 10 fibres of each type weredelivered by UCL to the ING out ofwhich 9 of each were to be used forscience. The 10th fibre of both typeswas manufactured in case of anybreakage.

The first stage after receiving thefibres was cutting them to the desiredlength. After this metal tubes wereglued over the fibre ends to make thegrounding, polishing and handlingeasier. The metal tubes were alsoconnected to the outer PTFE sleeve ofthe fibre, using heat shrinks, to giveextra strength and reduce the risk ofbreaking. Both ends of the fibres wereground and polished to a flatness of<¼ of a wavelength (632nm).

The body plate for the GMOS endconsists of 18 sapphire ball lenses oftwo sizes (3mm and 4mm diameter)and 18 silica optical windows (3mmdiameter, 300µm thick and 4mmdiameter, 400µm thick). The balls and

GMOS / bHROS Fibre Connection

M. F. Blanken (ING), G. Talbot (ING), M. Aderin (UCL)

the windows were glued in the bodyplate using UV-optical curing glue.Before the fibres were aligned in thebody plate a throughput test was doneto check the relative transmission ofthe 20 fibres. The best 18 fibres werealigned on top of the silica windowsand the sapphire ball lenses in thebody plate. The alignment was doneusing a target that simulates theGemini telescope pupil (fibrepositioning tolerances were 0.02mm).After the alignment, the fibres wereglued in the body plate by using theUV-optical curing glue and super glue.

After the polishing, aligning and gluingthe fibres were sent to the UK forinstallation of the optics for the bHROSend. The fibres are now complete andare waiting to be installed betweenGMOS and the bHROS instruments inChile. bHROS will be fully integratedwith the telescope in 2004.

ING is experienced in fibre work aftermaking several successful fibre


2 7

I n June 2003 ‘vapour cleaning’, aconcept invented by ING staff,was used to clean the Isaac

Newton Telescope’s primary mirror(2.5m) for the very first time.

The primary mirrors of the telescopesat the Isaac Newton Group areregularly cleaned to decrease thefrequency of aluminising. Over the lastfew years ING has moved from annualaluminising to condition basedaluminising, only doing it when thereflectivity and scatter measurementsindicate it is needed. The advantageis that an extra three nights areavailable to observers every year thataluminising is not carried out, not tomention the real risk of damage tothe primary mirrors every time theyare removed from the telescope foraluminising.

Regular cleaning is currently done bya method called “snow cleaning” or“CO2 cleaning”. This cleaning methoduses liquid CO2 that forms snowflakesonce it is in the open air. These

snowflakes hit the mirror surface andcapture dust particles. Thetemperature shock between the coldsnowflake and the “warm” mirror willeasily break the bond between the dustparticles and the mirror. The particlestogether with the snowflakes fall downonto the telescope structure. Therethe dust can be wiped away from thestructure. This way of cleaning themirrors is quick and easy restoringthe reflectivity by about 1–2% anddecreasing the scattering.

Unfortunately stains like water andoil cannot be removed using thismethod. A better way of cleaning themirror is to use water, soap andnatural sponges. First we wet themirror surface with water to flushaway all the big dust particles. Bydabbing and with the use of soap onthe sponges the water and oil stainscan be removed. The rest of the soaphas to be washed away by using waterbefore drying. The best way of dryingis to keep the surface wet until thevery last moment when the water is

blown away with filtered clean air. Allthe dust and most of the heavy stainscan be removed using this method.The reflectivity and scattering can berecovered to values close to thoseretained after aluminising. Thereforethis method is much better than the“CO2 cleaning”method.

A disadvantage of the “washing in situ”method is that it uses roughly 5–10litres of water per square meter. Thiscan be a problem when a copiousamount of water is running aroundmirror cells and associated equipment.Particularly electronics have to beprotected. So normally novel ideashave been developed to seal the mirroror optical component to stop the waterleaking around the telescope whichreduces the risk of water damage. Byusing the “water vapour method” only1–2 litres of water is used per squaremeter. The advantage is optical resultsequal to “water washing” without therisk of water damage. The smallamount of water used is easilycontrolled with sponges or towels

Do It Dry… INT Primary “Vapour Cleaning ”

M. F. Blanken, A. K. Chopping, K. M. Dee (ING)

projects. One project in particular,“Small fibres” consisted of 160 fibreswith a core diameter of 90µm for theAutofib2 (robotic positioner)/ WYFFOS(optical spectrograph) commissionedin July 2001 (see also ING Newsl., 4,26 and ING Newsl., 5, 19 for moreinformation and first light report). Theprocedures and experience of the“Small fibres” project were used in theGMOS/bHROS project. ING is activelylooking for more fibre work fromexternal institutes for the future.

For more information on the GMOS/bHROS project please visit thefollowing sites:

Gemini South telescope:http://www.gemini.edu/

HROS project page:http://www.osl.ucl.ac.uk/hros/

/new/fm-index.html ¤

Maarten Blanken ([email protected])

Figure 1 (left). Fibre grounding andpolishing. Figure 2 (top right). Fibres inbody plate gluing. Figure 3 (bottom right).Metal tube gluing.


2 8

“water washing” method, sponges anddabbing still need to be applied to themirror surface after the wetting.

The result of the washing of the INT2.5m primary was so successful thatplans are made to repeat this procedureon the William Herschel Telescopeprimary (4.2m). This is believed to bethe very first time that such a processhas been used on a major telescopemirror anywhere.¤Maarten Blanken ([email protected])

Vapour cleaning (left) and drying (right) INT primary mirror.

Satellites and Tidal Streams, an ING–IAC Joint Conference

O n May 26–30, 2003 ING, jointly with the IAC, organized the third major astronomical conference on La Palma,with the title “Satellites and Tidal Streams”. As with previous conferences, generous financial support was

provided by the Excmo. Cabildo Insular de La Palma and the Patronato de Turismo. The venue was the pleasantseaside resort of Los Cancajos, a few kilometers south of the main town of Santa Cruz de La Palma.

Current cosmological models predict that galaxies form through the merging of smaller substructures. Satellites andtidal streams might then represent the visible remains of the building blocks of giant galaxies. They therefore provideimportant information on the merging history and galaxy formation in the Universe. In this conference theobservational evidence for substructures, their internal structure and their dynamical evolution and disruptionwithin the tidal field of the host galaxy was discussed and confronted with theoretical cosmological predictions ofhierarchical merging and galaxy formation. With some 90 participants, including ‘old hands’ as well as a healthycontingent of young astronomers, the conference underlined the vibrant developments in this field and was a great success !

placed at the bottom of the telescopestructure.

The ING invested in 3 industrialvapour cleaners to be used for the“vapour cleaning” process. Before themachines were used on a telescopemirror, extensive tests were done onsimilar coated mirrors. It was foundthat it was very difficult to cause anydamage to the aluminium coating.Indeed only one test, which involvedholding the vapour stream only acouple of centimetres away from thesurface and in one position for 20minutes caused a slight degradationof the coating.

The primary advantage of vapourcleaning starts with wetting the mirror.For this part of the procedure a soapyvapour can be used by pre-mixingwater with soap. By wetting the mirrorthis way, the soapy vapour will startcleaning whilst removing the largedust particles. The vapour is heated

to a temperature of about 35 ºC.Therefore the temperature shockbetween the warm vapour and thistime the “cold” mirror helps to releasethe particles from the mirror (reverseof the “CO2 cleaning” method). Beforedrying the mirror, the soap can becleaned away from the surface and thesteam can keep the surface wet. Evenwithout touching the mirror surfacethe “vapour cleaning” will give a betterresult than the “CO2 cleaning”. Finallyto achieve the same results as the


2 9

A daptive Optics has been thecentre piece of ING’sdevelopment programme for

some years now. First results of theNAOMI AO system at the WHT havebeen presented in earlier issues of thisnewsletter. As ING is climbing thesteep learning curve of adaptive optics,the time was considered ripe to compareour experience at the WHT with that ofother telescopes with many more yearsof experience. In order to keep theworkshop well focussed and encouragethe best opportunities for debatingresults only a small number ofparticipants were invited to attend.Key invited guests included NorbertHubin from the European SouthernObservatory, Francois Rigaut fromGEMINI, Stefan Hippler from the MaxPlanck Institute for Astronomy, andEric Steinbring from the Centre forAdaptive Optics. But apart from theinvited guests, we also had excellentcontributions from Adriano Ghedina ofthe Telescopio Nazionale Galileo, whereadaptive optics features as part of theinstrument set, and from NicholasDevaney of the GTC 10-m telescopeproject. Plans for GTC include an AOsystem as part of their second-generationinstrument suit. Presentations ondesign and current performance ofNAOMI and the OSCA coronographwere given by Richard Myers fromDurham University, and by ChrisBenn and Sebastian Els from the ING.

Presentations and discussions includedaspects such as performance expectationsand reality of operational AO systems;performance characterisation; specificproblems and advantages of segmentedand continuous deformable mirrors;calibration and data reduction aspects.For the AO group at ING this sharingof experience and open discussion hasbeen an extremely useful event whichhelped the team to focus on keyquestions with some of the worldspecialists in the field.¤


NAOMI Workshop

Personnel MovementsThe most difficult aspect of the changes ING is going through is that several of our personnel haveleft or will be leaving ING. These colleagues have helped building ING and played a role indelivering the service to the community. As a consequence of these changes, both MichaelSimpson and Rachael Miles recently left ING.

Theresa Dorward, working in the administration group, is now finding fortune elsewhere, whilstBetty Vander Elst joined this group on a part-time basis. We’re very pleased that Chelo Barretohas returned to her original post after a three-year tour to work at the Joint Astronomy Centre onHawaii.

Begoña García and Johan Knapen came to the end of their tours and returned to their homeinstitutes in Tenerife and Hertfordshire, respectively. Last year, a new support astronomer, PierreLeisy, started work at ING under the agreement with the IAC. Also joining the astronomy groupas a short-term EU-funded Marie-Curie fellow has been Ilona Soechting.

Two engineers joined ING, also under the IAC agreement: Andy Hide will lead the Telescopes andInstruments group, while Olivier Martin will become primarily responsible for looking after thetelescope systems.

Snapshots and participants of the NAOMI Workshop 9-11 January 2003.

VIP Visitors

A natoly Karpov, world chess champion 1975– 85 and 1993–99, visited the William HerschelTelescope in November 2002 (see picture on the right), accompanied by the presidents of the

chess federations of La Palma and of the Canary Islands. A few days earlier, he played 18simultaneous matches in Gran Canaria, half of them via internet with opponents on other islands.The La Palma challenger was Chris Benn, manager of theWilliam Herschel Telescope (the sponsors of the eventwanted somebody in a remote location), playing from acomputer in the observatory with members of the localchess federation acting as referees. Having 18 times as longas Karpov to think about each move was encouraging,but by move 15, Karpov’s pieces had somehow taken overthe centre of the board. Then Chris made a weak move,and Karpov very rapidly demolished his defences andcheckmated on move 24. He won the other 17 games too.Other VIP visitors were Josep Piqué (Spanish Scienceand Technology Minister), Annejet Meijler (director ofthe Physical Science Council of NWO) and Richard Wade(Director of PPARC’s Programmes). ¤

Javier Méndez ([email protected])

OTHER NEWS FROM ING


3 0

News from the Roque

S ince the last Newsletter, there have been many developments at theobservatory. The most significant ones are those focussing on the10-m GRANTECAN telescope, where the building, services and dome

have now largely been completed. At the time of writing this, the azimuthbearing is being mounted. The next several months will see the erection of thetelescope structure. If you want to monitor progress on how the telescope isbeing erected, see http://www.gtc.iac.es/webcam_s.asp.

The MAGIC Cherenkov telescope, officially inaugurated together with theMercator telescope, on 10 October, has dramatically changed the skyline of theobservatory. This 17-m telescope, out in the open, is now being fitted out withits segmented mirrors that later this year will catch the photons of Cherenkovlight from high energy air showers. The HEGRA experiment, often referred toby visitors as the bee hives that were constructed in the same area, has beendismantled and removed.

The Liverpool telescope keeps making good progress. Some setbacks with theenclosure are being tackled, while the telescope structure is now essentiallycomplete and the optics were recently put into the telescope. The Liverpooltelescope was the centre of attention in May, as it was inaugurated bydignitaries from the UK and Spain.

In December La Palma was hit by a storm with exceptionally strong winds. Thestorm not only wreated havoc in the banana plantations on the island, but alsocaused the MERCATOR dome to suffer serious damage, sufficiently to stopoperation for some time while a new dome was ordered. The adjacent pictureshows how the new dome is being seated on top of the building.

The sometimes very strong winds hitting the island, under the rightatmospheric conditions give rise to weird cloud formations. Last year Michielvan der Hoeven was lucky to be in the right place at the right time to take theadjacent remarkable picture, showing a dome-shaped cloud overarching thetelescopes, lit by the setting Sun. This picture was one of the centre pieces of anexhibit of exceptional cloud formations organised by the aviation authorities onLa Palma.

ING is participating in the development of SuperWASP, a robotic set ofcameras that will monitor a very large part of the sky every night. The projectis led by the Queen’s University of Belfast. The system will sit in its ownenclosure that is being erected over the summer, located not far from the JKT.More news on this project will be presented in the next issue of the INGNewsletter.

If you drive up to the WHT you will see on your left-hand side a slender towerwith a small telescope at the top. This is a solar seeing monitor in support ofthe site testing campaigns for the planned Advanced Technology SolarTelescope (ATST), a 4-m solar telescope under study in the US. La Palma is oneof the few pre-selected sites for this telescope.¤


From top to bottom: MAGIC telescope near completion (credit Lise Autogena);MAGIC telescope and adjacent control room under construction; inauguration of

Liverpool Telescope on 7 May; replacement of damaged MERCATOR telescope; afantastic cloud over La Palma (credit Michiel van der Hoeven); SuperWASP building.


3 1

BBC’s All Night Star Party!

C oinciding with the closest approachof Mars to Earth in the last 60,000years, BBC Two had a party. The

All Night Star Party, a special live OpenUniversity programme for BBC Two, tookplace on 23 August night and lasted forone hour and a half.

In the course of this special programmeBBC Two handed over the Isaac NewtonTelescope to 600,000 viewers giving themthe chance to point the telescope tostunning objects live and see the imageson screen and online as they came outfrom the Wide Field Camera. Theprogramme also focused on severalaspects of British amateur andprofessional astronomy, in particular, theBeagle 2 Mars lander and, of course,obtaining an image of Mars live. Thislatter task was the responsability of twoamateur astronomers, Damian Peach andJohn Mills, who were based on the roof ofINT’s building.

The event was followed by 400 amateursat Jodrell Bank where the main broadcastcentre had been placed.

I would like to thank all ING staff for theimpressive effort made for this big eventand without whom this couldn’t havebeen possible. I would also like to thankall the people involved at the OpenUniversity and the BBC, in particular,Peter Brown, programme producer, MartinMortimore, La Palma broadcast director,and Chris Riley, presenter on La Palma.¤

Javier Méndez ([email protected])

Top: Online live feed of images. Middle:Presenter Chris Riley and support astronomerRomano Corradi. Bottom: Image of Marsobtained by Damian Peach and John Mills fromINT’s roof.

Seminars Given at INGVisiting observers are politely invited to give aseminar at ING. Talks usually take place inthe sea level office in the afternoon and last forabout 30 minutes plus time for questionsafterwards. Astronomers from ING and otherinstitutions on site are invited to assist. Pleasecontact Danny Lennon([email protected])and visit this URL: http://www.ing.iac.es//Astronomy/science/seminars.html, formore details. These were the seminars given inthe last 18 months:

Sep 18. Simon Jeffery (Armagh Obs.), “The results ofbinary white dwarf mergers”.

Oct 29. Michael Pohlen (IAC), “The nature of stellar disktruncations in galaxies”.

Nov 7. Mario Melita (Queen Mary, London), “Thedynamical structure of the Kuiper Belt”.

Nov 21. Jorick Vink (Imperial College), “The winds fromthe most luminous stars”.

Nov 27. Hugo Schwarz (CTIO-NOAO), “The SOARtelescope”.

Dec 10. Juan Cortina (Universitat Autonoma deBarcelona), “The MAGIC telescope”.

Dec 17. Xuefei Gong (Nanjing, China), “The SOARtelescope”.

Jan 13. Ivo Saviane (ESO Chile), “The luminosity-metallicity relation of dwarf irregular galaxies”.

Jan 27. John Taylor (Keele), “Eclipsing binaries in openclusters”.

Jan 31. Birgitta Nordstrom (Lund, Sweden &Copenhagen, Denmark), “Nucleosynthesis in the EarlyGalaxy”.

Feb 18. Paul Harding (Case Western Reserve, USA),“Star Streams in the Milky Way: Fragments of itsHistory”.

Feb 27. Laura Colombon (ING), “Kinematicsperturbations and low activity galaxies connection”.

Feb 28. Sebastián Sánchez (Potsdam), “Integral fieldspectroscopy at the AIP”.

Mar 12. Sebastian Els (ING), “Planet formation: a newway to observe them forming”.

Mar 18. Gijs Nelemans (IoA-Cambridge), “Observingdouble white dwarfs: test for common envelope theory,type Ia supernova progenitor models and gravitationalwave noise predictions”.

Mar 25. Eran Ofek (Tel Aviv University), “Measuring thetime delay of the lensed quasar HE1104–180”.

Apr 21. Daniela Lazzaro (Observatorio de Rio deJaneiro), “Spectroscopic observations of asteroids: theS3OS2 and Vestoids Project”.

Apr 24. Ilona Söchting (ING), “Environment of Quasars”.

May 7. Giangiacomo Gandolfi (CNR, Roma, Italy), “ShortGRBs: an unsolved enigma”.

May 8. Olga Kuhn (JAC, Hawaii), “Probing the faint endof the z>3 quasar luminosity function”.

May 15. Gloria Andreuzzi (Osservatorio Astronomico diRoma), “VLT-FORS1 observations of NGC 6397:Evidence for Mass Segregation”.

Jun 5. Humberto Campins (University of CentralFlorida), “Comets and Origin of Earth’s Water”.

Jul 2. Simone Marchi (University of Padova, Italy),“Spectroscopic Investigations of Near-Earth Objects”.

Nov 26. Silva Järvinen (NOT), “Photometric Study ofYoung Active Stars”.

Other ING Publications and Information Services

[INGNEWS] is an important source of breaking news concerning current developments at the ING,especially with regard to instruments.

You can subscribe to this mailing list by sending an email to [email protected] with themessage subscribe ingnews in the body. Please leave the subject field and the rest of the body of themessage empty.

Once subscribed, you can subscribe a colleague by sending to [email protected] thecommand subscribe ingnews your_colleague’s_ address. To unsubscribe from [INGNEWS] send [email protected] the command unsubscribe ingnews. More information on [INGNEWS]and all sent messages can be found on this web page: http://www.ing.iac.es/Astronomy//science/bulletin/.

Recent and old ING’s Technical Notes can be downloaded from:http://www.ing.iac.es/Astronomy/observing/manuals/man_tn.html.

Other ING publications are available on-line at the URLs below:

In-house Research Publications: http://www.ing.iac.es/Astronomy/science/ingpub/Annual Reports: http://www.ing.iac.es/PR/AR/Press Releases: http://www.ing.iac.es/PR/press/


3 2

TELESCOPE TIME

I t is important that applicants fortelescope time familiarisethemselves with the latest news

on instrumentation and detectorcombinations on offer, as well as withour scheduling restrictions. For thevery latest news always refer to theING web pages, homepagehttp://www.ing.iac.es. The ING’sgeneral scheduling constraints weresummarised in the first issue of theNewsletter and will not be repeatedhere, please refer to that issue, whichis also available on our publicinformation web pages. Due to theincreasing interest shown by thecommunity in applying to bring newvisitor instruments to the WHT wehave introduced a technical appraisalform to try to smooth the transitionof these instruments from thelaboratory to the telescope. This formis linked to the New VisitorInstruments web page atwww.ing.iac.es/Astronomy/observing/

/NewVisitorInstruments.html and itmust be completed and submittedalong with any national applicationform which proposes bringing a newvisitor instrument to the WHT.

What’s New

The year 2003 saw many changes atthe ING. On the positive side, and froma visiting astronomer’s point-of-view,we saw the commissioning of theintegral field spectrograph OASIS atthe AO focus of the WHT (page 21),plus the first very successfulcommissioning run of the IR imagingspectrograph LIRIS on the WHT (seethe cover page and page 15 of thisissue). OASIS is currently available tovisiting observers, prospectiveapplicants should contact Chris Benn([email protected]) for help and

information. We hope to acceptproposals for LIRIS in semester 2004B,pending the success of itscommissioning runs in 2004A. Usersshould note that for imaging, LIRISshould provide very similar capabilitiescompared to INGRID, and thereforeit is envisaged that LIRIS will replaceINGRID as the default Cassegrain IRimaging device in the future (INGRIDremaining at the AO focus).

As mentioned in the preceding section,visitor instruments continue to bevery successful in acquiring observingtime at ING. Sometimes an opportunityarises to offer these instruments forservice mode observing, with thecollaboration of their developmentteams of course. ULTRACAM, anultra-fast, triple-beam CCD cameraprovided such an opportunity in 2003,we thank Vik Dhillon for hiscooperation in this venture. Theavailable ULTRACAM service timewas hugely oversubscribed and weapologise to the many applicants whodid not receive any observations.However we hope to offer theinstrument again in 2004, theannouncement of opportunity will besent via the usual [INGNEWS] bulletin.

Other major changes have been thediscontinuation of the JKT as acommon user telescope, and thedecommissioning of IDS on the INT.We have also withdrawn TelescopeOperator support from the INT, whichis now a single-instrument telescopehaving just the WFC. Night-timesupport on the INT will be providedby the ING student support group forthe first night of each observing runonly, although an ING astronomerwill continue to act as the scientificcontact for each observing run. Whilethe INT/WFC is a rather easytelescope/instrument combination fora single user to manage, applicantsare reminded that it is inadvisable tosend unaccompanied inexperiencedobservers (student or otherwise) tothis telescope. Furthermore if theobserving programme is demanding,perhaps requiring a lot of real-time

interaction, it is suggested that morethan one observer should be present.

The International Scientific Committee(CCI) of the Roque de los Muchachos(ORM) and Teide (OT) observatoriesinvites applications for InternationalTime Programmes (ITP) on telescopesinstalled at these Observatories. TheITP offers up to 5% of the observingtime, evenly spread throughout theyear and the lunar cycle. An ITPproposal can request observing timeover a period of up to two subsequentyears. Full details of the scheme fornight-time telescopes can be found athttp://www.iac.es/gabinete/cci/

/tinoc1.htm. Proposals are consideredon an annual cycle and the closingdate for submission of proposals to the2004 ITP is Friday 6th February, forprojects which may start during thefall of the same year.

During 2004 it is expected that limitedaccess to ING telescopes will be grantedto all EU astronomers under theauspices of Opticon, funded by EU’sSixth Framework Programme. Detailsare expected to be announced soon,interested parties should refer tohttp://www.otri.iac.es/eno/. ¤

Danny Lennon ([email protected])

Applying for Time

Danny Lennon(Head of Astronomy, ING)

Important

DEADLINES FOR SUBMITTING APPLICATIONS

UK PATT and NL NFRA PC: 15 March, 15 September

SP CAT: 1 April, 1 OctoberITP: http://www.iac.es/gabinete/cci/

SEMESTERS

A: 1 February – 31 JulyB: 1 August – 31 January

ONLINE INFORMATION ON APPLYING FOR

TIME ON ING TELESCOPES

http://www.ing.iac.es/Astronomy/

http://www.ast.cam.ac.uk/ING/Astronomy/


3 3

Telescope Time Awards Semester 2003AFor observing schedules please visit this web page:http://www.ing.iac.es/ds/sched/.

William Herschel Telescope

UK PATT

– Almaini (IoA), Measuring black hole masses in narrow-line Seyfert 1 galaxies.W/2003A/63

– Charles (Southampton), Probing the accretion geometry of a quiescentblack hole. W/2003A/52

– Croom (AAO), A deep wide-field infrared survey for QSOs. W/2003A/4– Dhillon (Sheffield), Recurrent novae as Type Ia supernova progenitors.

W/2003A/8– Ivison (ATC), A narrow-band imaging survey of SCUBA galaxies. W/2003A/14– James (John Moores), Cluster evolution and the origin of starburst dwarf

galaxies in Abell 1367. W/2003A/40– Jeffery (Armagh Obs.), Physical parameters for helium-rich subdwarf B

stars —an unexplored evolutionary sequence. W/2003A/36– Jeffery (Armagh Obs.), Analysing sdB star companions to test binary star

evolution theory. W/2003A/51– Kleyna (IoA), Dark matter in the UMi dwarf spheroidal. W/2003A/17– Knapen (Hertfordshire), Stellar kinematics of the bar and circumnuclear

region of M100. W/2003A/65– Kodama (NAO, Tokyo), History of galaxy mass assembly in the hierarchical

universe at z∼1. W/2003A/12– Marsh (Southampton), ULTRACAM observations of interacting binary

stars. W/2003A/37– Meikle (ICL), Detailed study of the physics of nearby Type Ia supernovae.

W/2002B/23 (override, long term)– Meikle (ICL), Direct detection and study of supernovae in nuclear starbursts.

W/2002B/56 (long term)– Merrifield (Nottingham), Determining the dynamics of round elliptical

galaxies using the Planetary Nebula Spectrograph. W/2003A/38– Miller (Oxford), Wide-separation gravitational lenses from the 2dF QSO

Redshift Survey. W/2003A/33– Nelemans (IoA), Testing common envelope theory and SN Ia progenitor

models with double white dwarfs. W/2003A/25– Page (Mullard Space Science Lab), Optical identification of X-ray sources

in the 13H XMM-Newton/Chandra spectroscopic survey. W/2003A/42– Poggianti (OAP), Star formation and morphological evolution of galaxies

in clusters. W/2002B/28 (long term)– Pollacco (QUB), Characterising the Planetary Nebula binary central star

population. W/2003A/22– Rawlings (Oxford), FLAGS —the First Look Active Galaxy Survey. W/2003A/39– Roberts (Leicester), A spectroscopic study of the counterparts and

environments of ultraluminous X-ray sources. W/2003A/27– Smith (Hertfordshire), Spectropolarimetric constraints on the broad-line

region in narrow-line Seyfert 1 galaxies. W/2003A/18– Smith (Hertfordshire), Scattering geometries and the broad-line region in

radio-quiet Quasars. W/2003A/20– Tanvir (Hertfordshire), The origin and physics of Gamma-Ray Bursts.

W/2003A/30 (override)– Wilkinson (IoA), Constraining the structure of Draco’s dark halo —radial

velocities at large radii. W/2003A/35

NL NFRA PC

– Douglas (Kapteyn), Determining the dynamics of round elliptical galaxiesusing the Planetary Nebula Spectrograph. w03an008

– Förster Schreiber (Leiden), Near-infrared snapshot survey for brightlensed red high-redshift galaxies. w03an001

– Habing (Leiden), Census of asymptotic giant branch stars in northernLocal Group galaxies. w03an009

– Jarvis (Leiden), The Fundamental Plane and black hole masses of z=0.5radio galaxies. w03an004

– Thi (Amsterdam), Gas and dust in the protoplanetary disk around theHerbig AeBe star HD 141569. w03an007

– Wijers (Amsterdam), The origin and physics of Gamma-Ray Bursts.w03an005 (override)

– de Zeeuw (Leiden), SAURON mapping of the Virgo ellipticals. w03an003

SP CAT

– Abia (Granada), Production of Li in carbon stars and its metallicitydependence. W6/2003A

– Arribas (STSCI), INTEGRAL spectroscopy of galaxies, ULIRGs, gravitationallenses and QSOs. W25/2003A

– Balcells (IAC), Bi-dimensional spectroscopy of galactic bulges. W26/2003A– Castro-Tirado (IAA), The nature of the GRBs. W5/2003A (override)– Gallego (Complutense, Madrid), The evolution of the Star Formation Rate

density of the universe up to z=0.8. W17/2003A– García-Lario (ESA-VILSPA), Subarcsecond observations of PNe

precursors and young Proto-Planetary Nebulae. W22/2003A– Gizani (CAAUL, Lisboa), Rings in powerful radio galaxies. WG13/2003A– González (IAC), Spectropolarimetry of SW Sex systems. W18/2003A– Herrero (IAC), Metal abundances in Cyg OB2. W24/2003A– Iglesias (Marseille), A redshift survey of a UV-selected sample of cluster

galaxies. W2/2003A– Pascual (UCM), Physical properties and chemical abundances of the population

of current star-forming galaxies at z=0.24. W28/2003A– Pohlen (IAC), A test of the bar-peanut connection in a bulge-less galaxy.

W16/2003A– Ruiz-Lapuente (Barcelona). Stellar companions to supernovae. W1/2003A– Sánchez (IAC), Direct detection of giant planets around young nearby

stars. W19/2003A– Shahbaz (IAC), High time resolution optical studies of quiescent X-ray

transients. W15/2003A

Spanish Additional Time

– Barrado (LAEFF-INTA), Brown dwarfs in open clusters: the substellarmass function and the new lithium age scale. W31/2003A

– Cepa (IAC), The OTELO project: deep BRI survey of GROTH and SIRTF-FLS. W32/2003A

– Cristóbal (IAC), A study of extreme star-forming galaxies at high-z.W33/2003A

– Vílchez (IAA), A search for star forming galaxies in nearby clusters.WI15/2003A

TNG-TAC

– Fasano (OAP), Star formation and morphological evolution of galaxies innearby clusters with WYFFOS. T061

– Trevese (Roma), Investigating the nature of Low Luminosity ActiveGalactic Nuclei (LLAGN). T057

Isaac Newton Telescope

UK PATT

– Benn (ING), Star-formation rate at z>4; searching for the epoch ofreionisation. I/2003A/33

– Fitzsimmons (QUB), Rapid-response astrometry of potentially hazardousasteroids. I/2003A/28 (override)

– Gaensicke (Southampton), The cataclysmic variable population of theHamburg Quasar Survey. I/2003A/12

– Gilmore (IoA), Eclipsing K/M-dwarf binaries and the low mass stellarmass-luminosity-radius relations. I/2003A/29

– Howarth (UCL), Rotational velocities of Be stars. I/2003A/6– Keenan (QUB), The distances to the M15 and Complex K intermediate

velocity clouds. I/2003A/2– Maddox (Nottingham), Making monsters —the origin of brightest cluster

galaxies. I/2003A/23– Marsh (Southampton), Identification of faint stellar ROSAT sources, part

II. I/2003A/19– Meikle (UCL), Detailed study of the physics of nearby Type Ia supernovae.

I/2002B/9 (override, long term)– Morales-Rueda (Southampton), The key to binary star evolution. I/2003A/13– Snellen (Edinburgh), The space-density of high redshift FR I radio galaxies.

I/2003A/9– Tanvir (Hertfordshire), The Origin and Physics of Gamma-Ray Bursts.

I/2003A/20 (override)

NL NFRA PC

– Habing (Leiden), Monitoring of asymptotic giant branch stars in LocalGroup Galaxies. i03an006

– Helmi (Utrecht), Star streams and high velocity clouds in the Milky Wayhalo. i03an003


3 4

– Kuijken (Groningen), Sloan standard fields for the photometric calibrationof OmegaCAM. i03an001

– Wijers (Leiden), The origin and physics of gamma-ray bursts. w03an005(override)

UK/NL WFS Programmes

– Dalton (Oxford), The Oxford deep WFC survey. WFS/2002A/6– van den Heuvel (Amsterdam), The faint sky variability survey II.

WFS/2003A/1– McMahon (IoA), The INT wide angle survey. WFS/2003A/8– Walton (ING), The Local Group census. WFS/2003A/4– Watson (Leicester), An imaging programme for the XMM-Newton

serendipitous X-ray sky survey. WFS/2003A/3

SP CAT

– Casares (IAC), Simultaneous observations of Galactic gamma-ray sourceswith INTEGRAL. I6/2003A

– Casares (IAC), Radial velocity curve and mass function of LS5039microquasar. I7/2003A

– Castro-Tirado (IAA), The nature of GRBs. W5/2003A (override)– Deeg (IAC), Sample definition for exoplanet detection by the COROT

spacecraft. I13/2003A– Hammersley (IAC), A deep multi-wavelength survey of the Galactic plane.

I9/2003A– Martí (Jaén), Radial velocity curves of microquasars. I8/2003A– Montes (Complutense, Madrid), Spectroscopic characterisation of K and

M stars members of moving young groups. I10/2003A– Negueruela (Alicante), Determination of the orbit of the X-ray eclipsing

binary XTE J1855-026. I5/2003A– Vazdekis (IAC), Towards a robust scale of metallicities in globular clusters.

I11/2003A


– Balcells (IAC), Deep UV survey for COSMOS and OTELO. I17/2003A– Casares (IAC) On the age and formation history of Galactic black hole

binaries. I14/2003A– Vílchez (IAA), A search for star forming galaxies in nearby clusters. I15/2003A

Jacobus Kapteyn Telescope

UK PATT

– Brinkworth (Southampton), Star spots on magnetic white dwarfs. J/2003A/1– Bucciarelli (OAT, Italy), Photometric calibrators for the Palomar Sky

Surveys. J/2003A/3

– Fitzsimmons (QUB), Rapid-response astrometry of potentially hazardousasteroids. J/2003A/9 (override)

– James (John Moores), Derivation of [NII] contamination corrections forHα studies of star formation. J/2003A/13

– Keenan (QUB), Four-colour photometry of stars from the Palomar-greensurvey. J/2002B/2 (long term)

– Knapen (Hertfordshire), HII region statistics in spiral disks. J/2003A/15– Kuhn (JAC, Hawaii), Optical/UV continua of z>3 quasars. J/2003A/14– Morales-Rueda (Southampton), Companions to subdwarf B binary stars.

J/2003A/11– Norton (OU), Override multiwavelength observations of SXTs: black hole

accretion disk outbursts. J/2002A/2 (override, long term)– Pollaco (QUB), The overheating of irradiated atmospheres —observational

evidence. J/2003A/4– Prada (ING), RR Lyrae distances to the Sagittarius stream. J/2003A/12– Seigar (JAC, Hawaii), Quantifying the outer envelopes of cD galaxies.

J/2003A/10– Tanvir (Hertfordshire), The origin and physics of gamma-ray bursts.

J/2003A/5 (override)

SP CAT

– Calabresi (ARA, Italy), VRI photometry of Centaur Chariklo (10199) andKBO 20022GZ32 and 2002GO9. J1/2003A

– Castro-Tirado (IAA), The nature of GRBs. W5/2003A (override)– Kidger (IAC), Definition of an accurate 1-30 micron flux calibration

system for the GTC and SIRTF. J5/2003A– Martín (IfA, Hawaii), Photometry of stellar pairs of twins. J2/2003A– Negueruela (Alicante), Galactic structure towards the Galactic anti-centre.

J3/2003A– Pohlen (IAC), Spectral energy distribution of quasars. J4/2003A– Verdes-Montenegro (IAA), Characterizing the ISM in a sample of the

most isolated galaxies: Hα survey. J6/2003A

NL NFRA PC

– Douglas (Kapteyn), Photometry of PN.S targets. j03an002– Jonker (Amsterdam), Optical counterparts of LMXBs. j03an003– Mack (ASTRON), JKT imaging of radio sources at extreme stages of their

evolution. j03an001– Mack (ASTRON), JKT-imaging of a new sample of radio galaxies. j03an004– Wijers (Amsterdam), The origin and physics of gamma-ray bursts.

w03an005 (override)– van Woerden (Kapteyn), Updated epochs of maximum for RR Lyrae stars

projected on HVCs to be used for determination of HVC distances.j03an005

Telescope Time Awards Semester 2003B

For observing schedules please visit this web page:http://www.ing.iac.es/ds/sched/.

William Herschel Telescope

UK PATT

– Bower (Durham), The Sauron deep survey: exploring the Lyman-α haloesof massive galaxies at z=3. W/2003B/19

– Burleigh (Leicester), NAOMI followup observations of very low masscompanions to nearby white dwarfs . W/2003B/63

– Charles (Southampton), Determining system parameters of a soft X-raytransient in outburst. W/2003B/39

– Collins (John Moores), Environmental dependence of the fundamentalplane of brightest cluster galaxies. W/2003B/27

– Crowther (UCL), Wolf-Rayet stars in the metal-rich environment of M31.W/2003B/09

– Dalton (Oxford), Star formation at z~1. W/2003B/61– Dhillon (Sheffield), ULTRACAM observations of the transiting extrasolar

planet HD209458b. W/2003B/31– Dufton (Belfast), Spectroscopy of h + χ Persei to support VLT/FLAMES

survey. W/2003B/03– Fitzsimmons (Belfast), The 13th/14th November stellar occultation by Titan.

W/2003B/45

– Folha (Porto, Portugal), Excess emission in T Tauri stars: the missing link.W/2003B/15

– Folha (Portugal), Excess emission in T Tauri stars: the missing link.W/2003B/16

– Jarvis (Oxford), Weak lensing by cluster mass distributions traced by radiogalaxies at z= 0.5. W/2003B/37

– Marsh (Southampton), Stochastic variability of accretion discs. W/2003B/55– Marsh (Southampton), Orbital periods of post common envelope binary

stars from the SDSS. W/2003B/56– Mathioudakis (Belfast), High frequency oscillations in active cool stars.

W/2003B/26– McCaughrean (AIP, Germany), Spectral typing IR/X-ray selected brown

dwarf candidates in the Trapezium Cluster. W/2003B/64– McLure (Edinburgh), Exploring the connection between bulge/black-hole

mass and radio luminosity from z = 0 to z = 2. W/2003B/49– Meikle (ICL), Detailed study of the physics of nearby Type Ia supernovae.

W/2003B/02 (override)– Merrett (Nottingham), A deep kinematic survey of planetary nebulae in

M31. W/2003B/32– Nelemans (Cambridge), Testing common envelope theory and SN Ia

progenitor models with double white dwarfs. W/2003B/29– Nelemans (Cambridge), Follow-up of new AM CVn candidates. W/2003B/30– Østensen (ING), Resolving sdB binary systems with adaptive optics.

W/2003B/60


3 5

– Page (MSSL), Optical identification of faint X-ray sources in the 1H

XMM-Newton/Chandra spectroscopic survey. W/2003B/52– Pollacco (Belfast), Characterising the planetary nebula central star population.

W/2003A/22 (long term)– Smartt (Cambridge), An image archive to identify the progenitors of future

core-collapse supernovae. W/2003B/22– Smith (Hertfordshire), Scattering geometries and the broad-line region in

radio-quiet quasars. W/2003B/05– Smith (UCL), The massive star population of Wolf-Rayet galaxies. W/2003B/20– Vink (ICL), Spectropolarimetry of T Tauri stars. W/2003B/24– Wesson (UCL), ORL abundances and hydrogen-deficient clumps in PNe

with H-deficient central stars. W/2003B/62– Wills (Sheffield), Triggering the activity in giant elliptical galaxies. W/2003B/13

NL NFRA PC

– Douglas (Groningen), A deep kinematic survey of planetary nebulae in M31.w03bn014

– Emonts (Groningen), Origin and evolution of AGN activity in gas-rich radiogalaxies. w03bn005

– Groot (Nijmegen), Spectroscopic classification of the KISO survey: a searchfor AM CVn stars. w03bn017

– Klein Wolt (Amsterdam), Optical analogues of X-ray timing phenomenain X-ray binaries using ULTRACAM and RXTE. w03bn008

– Kuijken (Leiden), M31 microlensing: checking Mira contamination withNIR AO imaging. w03bn004

– Peletier (Groningen), Mapping the stellar dynamics and populations ofbarred galaxies. w03bn006

– Prins (ING), Spectroscopic confirmation of supernova remnants in M31.w03bn009

– Quirrenbach (Leiden), Line bisector variations for K giant stars with possibleplanetary companions. w03bn015

– Wijers (Amsterdam), The nature of gamma-ray bursts and their use ascosmological probes. w03bn003 (override)

– de Zeeuw (Leiden), A spectroscopic survey of the centers of intermediate-to-late spiral galaxies with SAURON. w03bn013

SP CAT

– Alfaro (IAA), Spectral mapping of a large star forming region of NGC 6946.W28/2003B

– Arribas (IAC), INTEGRAL spectroscopy of galaxies, ULIRGs, gravitationallenses, QSO’s hosts and planetary nebulae. W14/2003B

– Casares (IAC), Determining system parameters of a Soft X-ray transientin outburst. W2/2003B (override)

– Castro-Tirado (IAA), The nature of GRBs. W18/2003B (override)– Christensen (AIP, Germany), 3D spectroscopy of merger galaxies: clues to

star formation and AGN triggering. W11/2003B– Erwin (IAC), How many galactic bulges are imposters? W21/2003B– Negueruela (Alicante), Stellar parameters of XTE J1855–026 optical

counterpart. W7/2003B– Pérez (IAA), Kinematic rippling in spiral galaxies. W3/2003B– Pérez-Fournon (IAC), A depp WHT U-band extragalactic survey in SWIRE

fields. W27/2003B – Rebolo (IAC), The substellar-stellar connection in σ Orionis. W10/2003B– Ruiz-Lapuente (Barcelona), Supernovae at z=0.35–0.65: study of the nature

of the dark energy. W25/2003B– Ruiz-Lapuente (Barcelona), Stellar companions to supernovae. W24/2003B– Sánchez (AIP, Germany), 3D spectroscopy of merger galaxies: clues to

star formation and AGN triggering. W12/2003B– Shahbaz (IAC), High time-resolution imaging of the black hole X-ray

transient J0422+32. W20/2003B– Vílchez (IAA), Direct measuring of the inner abundance-gradient of M33

using bright PNe. W9/2003B– Zapatero (LAEFF, Madrid), Planets around young and bright stars in σ

Orionis. W8/2003B– Zurita (ING), Propagation of ionising radiation in HII inhomogenous regions.

W22/2003B


– Cepa (IAC), The OTELO project: deep BRI survey of SA68 and VIRMOS-0226. W17/2003B

– Herrero (IAC), WLRs of early B supergiants in M31/M33. W13/2003B

TNG-TAC

– Moretti (Padova), Ages and metal abundances of star clusters in M33. T032

Isaac Newton Telescope

UK PATT

– Drew (ICL), IPHAS — The INT/WFC photometric Hα survey of the northerngalactic plane. I/2003B/14

– Fitzsimmons (Belfast), Rapid-response astrometry of potentially hazardousasteroids. I/2003B/09

– Inskip (Cambridge), Understanding the stellar populations and alignmenteffect in distant radio galaxies. I/2003B/10

– Irwin (Cambridge), Probing the spatial distribution and structure of theMonoceros Ring. I/2003B/12

– McGroarty (Dublin), Final epoch observations of large scale outflows fromyoung stars. I/2003B/07

– McLure (Edinburgh), A photometric redshift study of radio galaxyenvironments. I/2003B/03

– Naylor (Exeter), What triggers star formation? A study of the recent starformation history of the Perseus Arm and Local Spur. I/2003B/11

– Ramsay (MSSL), WFC high time resolution survey — exploring a newtemporal parameter space. I/2003B/02

– Tanvir (Hertfordshire), The nature of gamma-ray bursts and their use ascosmological probes. I/2003B/13

NL NFRA PC

– Aragon (Groningen), Measuring Galaxy Spin Alignments along thePisces-Perseus Ridge in the Vicinity of A262. i03bn002

– van den Berg (OAB, Italy), Photometric variability of optically faint ChandraX-ray sources in M67. i03bn007

– Braun (NFRA), The STARFORM/Hα survey: Probing the recent history ofstar formation in spirals. i03bn005

– Habing (Leiden), Monitoring of asymptotic giant branch stars in LocalGroup galaxies. i03bn003

– Helmi (Utrecht), Star streams and high velocity clouds in the Milky Wayhalo. i03bn006

– Kuijken (Leiden), A survey for halo planetary nebulae in M31. i03bn001– Wijers (Amsterdam), The nature of gamma-ray bursts and their use as

cosmological probes. w03bn003 (override)

UK/NL WFS Programmes

– Walton (Cambridge), The Local Group census. WFS4– Watson (Leicester), An imaging programme for the XMM-Newton

Serendipitous X-ray sky survey. WFS3

SP CAT

– Castro-Tirado (IAA), The nature of GRBs W18/2003B (override)– Deeg (IAC), Sample definition for exoplanet detection by the COROT space

craft. I1/2003B– Erwin (IAC), The outer disks of S0 galaxies: clues to disk evolution. I10/2003B– Leisy (ING), IPHAS – The INT/WFC photometric Hα survey of the northern

galactic plane I6/2003B– López-Aguerri (IAC), Search of planetary nebulae in the intergroup region

of HCG 44. I7/2003B– Martínez-Delgado (MPIA, Germany), The building-blocks of the Milky

Way: searching for dwarf galaxy remnants around globular clusters.I12/2003B

– Ribas (Barcelona), Direct determination of the distance to M31 fromeclipsing binaries. I2/2003B

– Rosenberg (IAC), Formation and evolution of the Milky Way (III): the Galacticdisk. I9/2003B

– Vílchez (IAA), A search for star forming galaxies in nearby clusters. I5/2003B


– Balcells (IAC), Deep UV survey for COSMOS and OTELO. I11/2003B– Herrero (IAC), Detecting the blue massive star population to 5Mpc for

OSIRIS. I8/2003B

Abbreviations:

CAT Comité para la Asignación de TiempoNFRA Netherlands Foundation for Research in AstronomyNL The NetherlandsPATT Panel for the Allocation of Telescope TimePC Programme CommitteeSP SpainTAC Time Allocation CommitteeTNG Telescopio Nazionale GalileoUK The United KingdomWFS Wide Field Survey

Contacts at ING Name Tel. (+34 922) E-mail (@ing.iac.es)ING Reception 425400Director René Rutten 425421 rgmrHead of Administration Les Edwins 425418 lieHead of Astronomy Danny Lennon 425440 djlHead of Engineering Gordon Talbot 425419 rgtOperations Team Kevin Dee 405565 kmdTelescope Scheduling Ian Skillen 425439 wjiService Programme Pierre Leisy 425441 pleisyWHT Manager Chris Benn 425432 crbINT Manager Romano Corradi 425461 rcorradiInstrumentation Technical Contact Tom Gregory 425444 tgregoryFreight Juan Martínez 425414 juanPublic Relations Javier Méndez 425464 jma

Table of ContentsMessage from the Director . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1The Isaac Newton Group of Telescopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2The ING Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2The ING Director’s Advisory Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2The ING Newsletter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2F SÁNCHEZ, “IAC Partnership with ING” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

SCIENCE

J T KLEYNA, M I WILKINSON, G GILMORE, N W EVANS, “First Evidence for an Extended Dark Halo in the DracoDwarf Spheroidal” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

R G BOWER, S L MORRIS, R BACON, R WILMAN, M SULLIVAN, S CHAPMAN, R L DAVIES, P T DE ZEEUW, “The SAURONDeep Field: Investigating the Diffuse Lyman-a Halo of Blob1 in SSA 22” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

T P ROBERTS, M R GOAD, M J WARD, R S WARWICK, “The Unusual Supernova Remnant Surrounding theUltraluminous X-Ray Source IC 342-X1” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

R L M CORRADI, L MAGRINI, P LEISY, C DAVENPORT, “The Census of Planetary Nebulae in the Local Group” . . . . . . . . . . . . 11

TELESCOPES AND INSTRUMENTATION

J A ACOSTA PULIDO, E BALLESTEROS, M BARRETO, R BARRETO, E CADAVID, J CARRILLO, S CORREA, J M DELGADO,C DOMÍNGUEZ-TAGLE, E HERNÁNDEZ, R LÓPEZ, A MANESCAU, A MANCHADO, H MORENO, J OLIVES, L PERAZA, F PRADA,P REDONDO, V SÁNCHEZ, N SOSA, F TENEGI, “First Commissioning of the IR Spectrograph LIRIS” . . . . . . . . . . . . . . . . . . . 15

S G ELS, S THOMPSON, P DOEL, P JOLLEY, THE NAOMI TEAM, “OSCA – The Coronographic Mask Device for NAOMI” . . . . 17T MORRIS, “Rayleigh Laser Guide Star Returns to the WHT” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18R WILSON, C SAUNTER, “SLODAR: Profiling Atmospheric Turbulence at the WHT” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18G TALBOT, A CHOPPING, K DEE, D GRAY, P JOLLEY, “Amazing GRACE” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19C BENN, G TALBOT, R BACON, “OASIS at the WHT” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21N O’MAHONY, “RoboDIMM — The ING’s New Seeing Monitor” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22R RUTTEN, “CONCAM — ING’s All-Sky Camera” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24S TULLOCH, “L3 CCD Technology” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25M F BLANKEN, G TALBOT, M ADERIN, “GMOS/bHROS Fibre Connection” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26M F BLANKEN, A K CHOPPING, K M DEE, “Do It Dry... INT Primary Vapour Cleaning” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

OTHER NEWS FROM ING

“Satellites and Tidal Streams ING–IAC Joint Conference” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28R RUTTEN, “NAOMI Workshop” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29J MÉNDEZ, “VIP Visitors” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29“Personnel Movements” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29R RUTTEN, “News from the Roque” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30J MÉNDEZ, “BBC’s All Night Star Party ! ” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31“Seminars Given at ING” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31“Other ING Publications and Information Services” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

TELESCOPE TIME

D LENNON, “Applying for Time” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32“Important” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32“Telescope Time Awards Semester 2003A” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33“Telescope Time Awards Semester 2003B” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

ISAAC NEWTON GROUP OF TELESCOPESRoque de Los Muchachos Observatory, La Palma

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