NEWSLETTER No. 8, September 2004 T HE I SAAC N EWTON G ROUP OF T ELESCOPES Dear Reader, In some aspects the last several months at the observatory, since the previous issue of this Newsletter, have been similar to previous years, and in other aspects there has been major change. To start with the latter, I refer to the very welcome news that the long-sought development of a laser beacon for adaptive optics at the William Herschel Telescope has been approved. Coincidentally, receiving 'green-light' for the project will take on a literal meaning when some two years from now the projection of green laser light will become a regular feature above the telescope. The scientific potential of having the full sky available to adaptive optics exploitation rather than only about 1% as in the case of 'classical' adaptive optics, is excellent. Now it is our task to build a working system, and then to scientifically exploit it. An introductory 1 Message from the Director Science Prospects with OASIS Spatially binned SAURON (left map) velocity field of NGC 4382 (Emsellem, E., et al., 2004, MNRAS, 352, 721) showing the outline of the OASIS field (right map) as obtained at CHFT (see article by Richard McDermid et al. on page 3). OASIS R-band images of a close binary (V mag ~ 9+10) in 0.5" natural seeing (“open loop”) and with NAOMI correcting the PSF (“closed loop”) to 0.2" FWHM.
Transcript
NEWSLETTER
No. 8, September 2004
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,
In some aspects the last several months at theobservatory, since the previous issue of thisNewsletter, have been similar to previous years,and in other aspects there has been majorchange. To start with the latter, I refer to thevery welcome news that the long-soughtdevelopment of a laser beacon for adaptive opticsat the William Herschel Telescope has beenapproved. Coincidentally, receiving 'green-light'
for the project will take on a literal meaningwhen some two years from now the projection ofgreen laser light will become a regular featureabove the telescope. The scientific potential ofhaving the full sky available to adaptive opticsexploitation rather than only about 1% as in thecase of 'classical' adaptive optics, is excellent.Now it is our task to build a working system, andthen to scientifically exploit it. An introductory
1
Message from the Director
Science Prospects with OASIS
Spatially binned SAURON (left map) velocity field of NGC 4382 (Emsellem, E., et al., 2004, MNRAS,352, 721) showing the outline of the OASIS field (right map) as obtained at CHFT (see article byRichard McDermid et al. on page 3).
OASIS R-band images of a close binary (Vmag~ 9+10) in 0.5" natural seeing (“open loop”) and withNAOMI correcting the PSF (“closed loop”) to 0.2" FWHM.
article on this exciting new project canbe found on the following pages. I wouldvery much welcome ideas andsuggestions from the user communitytowards this project.
Coming back to the first sentence of thisintroduction, activities at the observatoryhave been as intense as ever. The lastseveral months have once again seen arange of visiting instruments. Three ofthem were first-time visitors, each withtheir own very significant technical andastronomical challenges. There wasCIRPASS, the near IR spectrographfrom Cambridge operating in multi-
object mode. There was PLANETPOLfrom Hertfordshire, measuring polarisationwith remarkable acuracy in an attemptto detect planets around stars. And therewas S-CAM2, deploying the second-generation of super-conducting tunneljunction detector technology for a rangeof science programmes. So yes, work atING has gone on as normal and hasn'tbeen boring for a single moment.
Enjoy this issue of the Newsletter, andnote that the editorial team would loveto receive contributions from our readers!
Apartado 321; E-38700 Santa Cruz deLa Palma; Canary Islands; Spain.Telephone: +34 922 425400Fax: +34 922 425401URL: http://www.ing.iac.es/
Editorial team: Javier Méndez, RenéRutten and Danny Lennon.Consultant: Johan Knapen.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 PDFformat. Notification of every new issueis given by e-mail using the [INGNEWS]mailing list. More information on[INGNEWS] can be found on page 23.Requests for one-off printed copiescan be emailed to Javier Méndez(jma@ ing.iac.es).
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 2350 m above sealevel at the Roque de LosMuchachos Observatory on theisland of La Palma, Canary Islands,Spain. The WHT is the largesttelescope of its kind in WesternEurope.
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 –
University of GroningenDr P. Crowther – University of SheffieldDr G. Dalton – University of OxfordDr R. García López – IACDr 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 SAURON survey has a spatialsampling of 0.94″×0.94″ per lenslet,therefore often undersampling themedian seeing at La Palma (0.7″FWHM). Towards the galaxy nucleus,however, there are often sharp,localised features in the kinematics,such as decoupled cores or centraldisks, as well as distinct stellarpopulations and ionised-gasdistributions. Such features may onlybe partially resolved in the SAURONdata, or perhaps not visible at all.
Additionally, at Hubble SpaceTelescope (HST) resolution, ellipticalgalaxies exhibit power-law centralluminosity profiles. The slope of thispower-law shows clear trends withcertain global properties, such as the
degree of rotational support, isophotalshape, and stellar populations. It istherefore crucial to fill the gap betweenthe medium (few 100s of pc) to large-scale (few kpc) structures probed withSAURON and the inner (<200pc)components probed by HST. We havethus begun a complementary studyon a subset of the SAURON sampleusing the OASIS spectrograph, duringits former life mounted on the Canada-France-Hawaii Telescope (CFHT),Hawaii. This follow-up survey is beingcontinued with OASIS at the WHT,with the aim of completing all E/S0sof the SAURON survey by spring 2005.Here we give an overview of thisfollow-up survey, and future prospectsfor using OASIS in this field.
The OASIS Spectrograph
The OASIS integral-field spectrograph,mounted behind the NAOMI AdaptiveOptics (AO) system (Benn et al., 2002,2003) in the GRACE Nasmythenclosure of the WHT (Talbot et al.,2003), was offered to the INGcommunity in semester 2004B, andwas awarded time during 15 nightsfor a variety of science projects. OASISis based on the TIGER lens-arrayconcept (Bacon et al., 1995) and isdesigned for high-spatial resolutionobservations, specifically with theassistance of AO. There is a selectionof gratings and filters available, givinglow and medium spectral resolutionmodes within the 0.43µm to 1µmwavelength range. Via the use ofdifferent enlargers, there is also arange of spatial samplings which canbe adapted to suit the available PSF.Figure 1 and Table 1 summarise the
THE ING NEWSLETTER No. 8, September 2004
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SCIENCE
Under the Microscope: Galaxy Centres with OASIS
R. McDermid1, R. Bacon2, G. Adam2, C. Benn3, E. Emsellem2, M. Cappellari1, H. Kuntschner4,M. Bureau5, Y. Copin6, R. L. Davies5, J. Falcon-Barroso1, P. Ferruit2, D. Krajnovic5, R. F. Peletier7,K. Shapiro8, P. T. de Zeeuw1
1: Leiden Observatory; 2: CRAL-Observatoire, Lyon; 3: ING; 4: STECF-ESO; 5: Dept. of Astrophysics, University of Oxford; 6: Institutde Physique Nucleaire de Lyon; 7: Kapteyn Institute; 8: UC Berkeley
E arly-type galaxies are thoughtto be among the oldest knownstellar systems, and as such
have experienced the full diversity ofevolutionary mechanisms at work inthe universe. They are cruciallaboratories for understanding howgalaxies form and evolve from earlyepochs until the present day. A keyaspect of unlocking their fossil evidenceis by studying the dynamics of starsand gas, and characterising the stellarpopulations. To this end, the SAURONsurvey (de Zeeuw et al., 2000, Peletieret al., 2001, de Zeeuw et al., 2002) hasundertaken a study of 72 representativenearby early-type galaxies and spiralbulges using the SAURON integralfield spectrograph at the WHT (Baconet al., 2001).
Figure 1. Spectral configurations of OASIS. Blue lines indicate the low-resolution (LR)modes (R∼1000); green lines indicate medium-resolution (MR) modes (1000<R<2000);and red lines indicate high-resolution (HR) modes (R>2000). The dichroics are requiredto isolate the science light from the NAOMI AO system.
Gas Kinematics: By subtracting theoptimal template, one obtains a residualspectrum in which the emission-linefeatures are revealed. We thendetermine the distribution andkinematics of the ionised-gas, byfitting the emission-line profiles ofthese continuum-free spectra withsimple Gaussians.
Line Strengths: The OASIS spectralrange contains a number of keyabsorption features which can be usedas diagnostic tools to determine theage and metallicity of the stellarpopulations within a galaxy. To removethe contaminating emission lines, theGaussian fits are subtracted from theoriginal data before measuring theabsorption line strengths. Finally, theabsorption line strengths are calibrated
onto the well-established LICK/IDSsystem (e.g. Trager et al., 1998).
Figure 3 shows an example of how theOASIS data can be used to revealcentral features of galaxies in theSAURON survey. The left panel of thisfigure presents the SAURON velocityfield of NGC 4382. There is a low-level‘kink’ in the zero-velocity (green)contour near the galaxy centre. TheOASIS data (right panel) clearly revealthis as a counter-rotating decoupledcomponent.
Figure 4 presents the OASIS stellar(left panel) and gas (right panel) velocityfields for NGC 2768. The stellarcomponent rotates around the apparentshort-axis of the galaxy. The gas,however, rotates around the apparent
No. 8, September 2004 THE ING NEWSLETTER
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available instrument modes. With theaddition of AO capabilities providedby NAOMI, OASIS is one of the mostversatile optical integral-fieldspectrographs currently in operation.
Observations
For this project, OASIS was configuredto give similar spectral coverage andresolution as SAURON by using theMR516 configuration. The data werereduced using the publicly availableXOasis software (Rousset, 1992)developed at CRAL (Lyon). Galaxyobservations were composed of two ormore exposures, which were mergedby first aligning the galaxy nucleusof the separate reconstructed images.Co-spatial spectra were then combined,taking into account the error spectrathat are propagated through thereduction. In order to provide reliable,unbiased measurements, the data cubesare binned in the spatial dimensionto a minimum signal-to-noise ratio of60 per pixel using the Voronoi 2D-binning developed by Cappellari &Copin (2003).
Results
From the 2D-binned data cubes, itis possible to derive the followingproperties:
Stellar Kinematics: These are derivedby directly fitting the spectra in pixel-space (Cappellari & Emsellem, 2004),which avoids contamination by nebularemission lines, which can often bestrong in the central regions of early-type galaxies (Figure 2). Templatemismatch was minimised by buildingan ‘optimal template’ from a libraryof stellar population models fromVazdekis (1999).
Table 1. OASIS spatial configurations.
Mode Enlarger Sampling FOV(mm) (") (")
Spectral 8.5 0.09 2.7× 3.712.5 0.14 4.0× 5.5
22 0.26 7.7×10.3
33 0.42 12.0 ×16.7
Imaging 62 0.02 37.6
Figure 2. Optimal template fit to the central spectrum of NGC 2768. The lower spectrumshows the residual emission lines after the template-fit, which are fitted using singleGaussians to obtain the gas properties. Vertical lines show regions around the emissionthat are excluded from the fit.
Figure 3. Spatially binned SAURON (left map) velocity field of NGC 4382 (Emsellemet al., 2004) showing the outline of the OASIS field (right map).
long-axis, perpendicular to the stars.This illustrates how we can separatethe stellar and gas properties, usingthe optimal template fit. There is someevidence of non-axisymmetry in thestellar velocity field, which mayindicate the presence of a bar.
Figure 5 presents a map of Hβabsorption strength (after emissionsubtraction) for the galaxy NGC 3489(left panel) showing a strong peak inthe central 1″, indicating a youngstellar population. The right panel ofFigure 5 quantifies this, plotting Hβabsorption strength against theabundance-insensitive metallicityindicator [MgFe50]' (Kuntschner etal.) from the OASIS data. The youngpopulation in the core of this galaxyindicates that it is in a post-starburstphase, with a luminosity-weighted ageof around 1.5 Gyr. Equivalent SAURONdata are also shown, illustrating thatboth data sets are consistent.
Future Prospects: NAOMI
The integral-field capabilities of OASISare ideal for exploiting the correctedPSF delivered by the NAOMI AOsystem, and commissioning resultsindicate that NAOMI is performingwell at optical wavelengths (Figure 6).There are several objects in our samplewhich have a suitable guide starnearby, for which we have beenallocated observing time to push thelimits of spatial resolution, andmeasure stellar motions close to theputative central supermassive blackhole residing at the galaxy centres.There are few targets in the sky withsuch conveniently placed bright stars,and so this project provides a glimpseof what will be possible on many targetswhen the GLAS laser guide-star systembecomes available in 2006. Moreinformation on GLAS can be found onthe web page: http://www.ing.iac.es/About-ING/Strategy/glas_web_announcement.htm.
Summary
The central regions of nearby early-type galaxies contain a wealth ofstructure and detail that we are onlyjust beginning to uncover. Galaxyproperties show connections on vastly
different scales, and by understandingthese relationships, we gain insightinto galaxy formation mechanisms.The OASIS follow-up of the SAURONsurvey will provide a unique data set
for a large sample of objects,complementing the panoramic viewdelivered by SAURON, and giving acomprehensive picture of galaxystructure.
THE ING NEWSLETTER No. 8, September 2004
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Figure 4. OASIS stellar (left) and ionized-gas (right) velocity fields for NGC 2768showing the decoupled rotation of the stars and gas. Isophotes from the reconstructedimage are overplotted, showing the total flux within each OASIS spectrum. Distortionof these isophotes indicates dust features.
Figure 5. Left panel: OASIS map of Hβ absorption strength in NGC 3489. Right panel:Hβ absorption strength versus an abundance-insensitive metallicity index, overplottedwith a grid of stellar population models from Vazdekis (1999). Open symbols: OASISmeasurements; filled symbols: SAURON measurements, binned in 1" circular annuli.Circles indicate measurements inside a 1" radius of the centre; triangular symbolsindicate measurements outside this radius.
Figure 6. OASIS R-band images of a close binary (Vmag~ 9+10) in 0.5" natural seeing(“open loop”) and with NAOMI correcting the PSF (“closed loop”) to 0.2" FWHM.
The first such object was discoveredby Warren et al. (1996) and theapplication of the SDSS survey forlenses at lower redshifts has beendemonstrated by Bolton et al. (2004).
Examining the results of an automatedsearch of the SDSS DR1 spectroscopicdatabase for emission lines fromputative high-redshift sources, oneparticular galaxy showed anunambiguous emission line detectionwith a somewhat weaker feature tothe blue. The emission line pair wasimmediately identifiable as emissionfrom [OIII] 4959, 5007. Not an entirelyunexpected occurrence but the unusualfeature of the detection was that thewavelength of the detection placed theemission at essentially zero radialvelocity. Querying the output of theemission line search for similar
detections produced more spectrashowing a similar signature. All of theobjects possessing [OIII] emissionoccurred in an approximately circularregion with a diameter of ∼1.5°, withnot a single detection anywhere elseon the sky. Investigation of SDSSspectra of stars, quasars and even skyfibres revealed further detections, allconcentrated in the same region of sky.
A series of checks fairly rapidlyeliminated the majority of instrumentalartifacts or transient phenomena asthe cause of the emission. Discreteenquires of the SDSS team producedthe news that [OIII] emission hadoccasionally been detected but thiswas due to auroral activity. However,the detection of the [OIII] emission intwo SDSS spectroscopic fields observedon different nights and confirmation
The Largest Known Planetary Nebula on the Sky
Paul Hewett and Mike Irwin (IoA, Cambridge)
T he enormous Sloan Digital SkySurvey (SDSS) spectroscopiccatalogue has many
applications but the discovery ofPlanetary Nebulae (PN) had not beenrecognised as among the potentialscientific returns. However, the INTrecently played a key role in theidentification of a record breakingPN discovered serendipitously fromthe SDSS.
The vast majority of PN in our owngalaxy have been identified via wide-field narrow-band Hα surveys of thetype currently ongoing using the INT(http://astro.ic.ac.uk/Research/Halpha/North/) or through wide-field low-resolution slitless spectroscopic surveys,with both techniques attempting toisolate objects showing very highequivalent width emission lines thatare characteristic of PN. The potentialof the relatively high-resolution,pointed spectra that make-up theSDSS spectroscopic database involveda serendipitous observation duringthe course of a search for high-redshiftgravitational lenses. The idea behindthe gravitational lens search is totarget luminous (massive) galaxies atintermediate redshifts, 0.2<z<0.6,which constitute the optimal line-of-sight for detecting gravitationallylensed background sources (Hewettet al., 2000). The population of high-redshift star-forming galaxies, manyof which possess strong Lyα emission,provide a high surface density ofreadily detectable background sources.
Figure 1. Spatial distribution ofspectra with detectable [OIII]4959, 5007 (dots), Hα (circles),and [NII] 6583 (crosses). Thehatched area indicates a regionwhere composite spectra alsoshow unambiguous evidence of[OIII] 4959, 5007 emission.Positions of objects with SDSSspectra for which no individualdetections were obtained arealso indicated. The dashedoutline shows the area includedin the narrow-band images ofFigure 2. The location of thewhite dwarf PG 1034+001 ismarked by a box.
Acknowledgments: It is a pleasure tothank the staff of the ING and CRALfor all their hard efforts in ensuringan efficient transfer and installationof OASIS at the WHT. Thanks also tothe CFHT staff for their support ofOASIS during its time there. ¤
References:
Bacon, R., et al., 1995, A&AS, 113, 347.Bacon, R., et al., 2001, MNRAS, 326, 23.
Benn, C. R., et al., 2002, ING Newsl., No.6, 21.
Benn, C. R., et al., 2003, ING Newsl., No.7, 21.
Cappellari, M. & Copin, Y., 2003, MNRAS,342, 345.
Cappellari, M. & Emsellem, E., 2004, PASP,116, 138.
Emsellem, E., et al., 2004, MNRAS, 352, 721.Kuntschner, H., et al., in prep.Peletier, R. F., et al., 2001, ING Newsl.,
No. 5, 5.
Rousset, A., 1992, PhD, Univ. J. Monnetde Saint-Etienne.
Talbot, G., et al., 2003, ING Newsl., No. 7, 19.Trager, S. C., et al., 1998, ApJS, 116, 1.Vazdekis, A., 1999, ApJ, 513, 224.de Zeeuw, P. T., et al., 2000, ING Newsl.,
of the continued presence of [OIII]emission from a spectrum obtained atthe MMT Observatory ruled out anexplanation due to a transientphenomenon. Combining spectrabeyond the boundaries of the regionwhere [OIII] emission was detected inindividual produced clear detectionsof [OIII] emission extending over aregion more than 2° in diameter.
A smaller number of individual spectraalso showed the presence of emissionfrom Hα and [NII] 6548, 6583. Thespatial distribution of the individualemission line detections revealedclear trends and composite spectra,made up from objects contiguous onthe sky, confirmed the trends andeven allowed the detection of [SII]6718, 6732. Figure 1 shows the spatialdistribution of line emission as derivedfrom the SDSS spectra.
Narrowband imaging of the centralpart of the region was undertakenduring a WFC survey run on the INTin 2003 May. The object is hard work,with integrations of 1200 and 2700sin Hα and [OIII] 4959, 5007respectively, necessary to allow thedetection of emission over the majorityof the field. However, the results wereunambiguous, with excellent
agreement between the surfacebrightness distribution evident in theINT images (Figure 2) and theemission line detections from theSDSS spectra. A striking feature ofthe images was the presence of awell-defined arc-like feature, perhapssuggestive of some form of shock.
A wide range of possible explanationsfor the emission line region wereconsidered without success. Then,following the INT observations, asearch of the region using SIMBADrevealed the presence, close to theregion with the strongest [OIII]emission, of a very nearby, extremelyhot DO white dwarf (PG 1034+001).The location of the white dwarfclinched the identification of theemission region as a PN. Thediameter of more than 2° makes theobject the largest known PN on thesky and Rauch et al. (2004) haveidentified evidence for an ionisedhalo some 10° across.
PG 1034+001 does not yet possessa parallax distance but thespectroscopic distance estimate of155+58 pc (Werner et al., 1995)means the PN is certainly the secondclosest known and a parallax distance
could confirm the nebula as the nearestPN to the Solar System. Theunambiguous detection of a PNassociated with a non-DA white dwarfis also a first. Determination of areliable age for the PN will helpconstrain timescales associated withthe late stages of evolution of post-asymptotic giant branch stars and theorigin of helium-rich white dwarfs. ThePN is certainly old, an estimate of theexpansion age and a kinematic ageestimate, derived from extrapolatingthe observed proper motion of PG1034+001 back to the origin of theradius of curvature of the arc feature,both suggest an age of ≅100,000 yr.The strongly enhanced [NII] emissionevident along the south westernboundary of the PN is also indicativeof the interaction of an old PN withthe surrounding interstellar medium.
The strength of the [OIII] emissionsuggests that imaging of other hotnon-DA white dwarfs might berewarding and we have begun such aprogramme with the INT incollaboration with Matt Burleigh(Leicester). The first run earlier thisyear suffered from poor conditions butpreliminary results suggest thedetection of at least one new PN. ¤
Figure 2. The left hand panel shows a mosaic of 6 INT WFC continuum–subtracted pointings in Hα+[NII] while the right panelshows the equivalent for [OIII]. The images are approximately 0.8° on a side with North to the top and East to the left. The locationof the white dwarf PG 1034+001 is indicated by a circle in the [OIII] image. Emission with complex structure is evident in thecentral regions of the images in both passbands. A well–defined arc, or boundary, is visible at center–right in the [OIII] image.
–43
WFC photometry, which shows theinhomogeneity of this system. Metal-poor/young stars are coded blue whilstmetal rich/older stars are coded red.This spectacular image shows inamazing detail the wealth ofinformation that the INT is helpingto reveal about the structure of thispreviously invisible region of galaxies.The most obvious piece of substructurevisible in Figure 1 is the giant stellarstream (visible in the south-east). Thisextends to near the edge of our survey—a projected distance of some 60 kpc(Ibata, 2001). In fact, by examiningthe systematic shift in the luminosityfunction of the stream as a functionof galactocentric radius, we find its
actual length is much greater than100 kpc (McConnachie, 2003). Thesimilarity of the colour of this featurewith the loop of material at the northof the survey suggests a connection:deep follow-up imaging using HST/ACSconfirms that they possess the samestellar population (Ferguson, 2004a).It seems likely that the northernfeature is an extension of the stream,after it has passed very close to thecentre of the potential of M31 (Font,2004; Ibata, 2001).
A second large stellar stream candidatehas also been identified with the INTWFC photometry (McConnachie,2004c). The visible part of this feature
Exploring Andromeda’s Halo with the INT
Alan McConnachie1, Annette Ferguson2, Avon Huxor3, Rodrigo Ibata4, Mike Irwin1, GeraintLewis5, Nial Tanvir3
1: Institute of Astronomy; 2: Max-Planck-Institut für Astrophysik, Garching, Germany; 3: Physical Sciences, University of Hertfordshire;4: Observatoire de Strasbourg, France; 5: Institute of Astronomy, University of Sydney, Australia.
T he structure of the outerregions of galaxies is a keyarea in which to look for fossil
remnants of the accreted masses fromwhich the galaxies that we see todayare thought to be built (Searle, 1978,White, 1978). The importance of theseregions has increased in recent yearsas cosmological theories of structureformation become more exact in theirpredictions, and the observationalinstrumentation required to conductthese detailed analyses becomes moresophisticated. Currently composed of165 individual pointings of the IsaacNewton Telescope Wide Field Camera(INT WFC), the M31 halo surveyconsists of photometry for over 7million sources, on a photometricsystem accurate to 2% over ~40 squaredegrees on the sky, in some placesprobing the halo of Andromeda out to6° (~80 kpc). Observations of 800–1000seconds in the Johnson V (V′) andGunn i (i′) passbands are deep enoughto detect individual RGB stars downto V′= 0 and Main Sequence starsdown to V′= –1. This unique datasethas provided, for the first time, apanoramic deep view of the stellar haloof a giant galaxy thought to be similarto our own Milky Way (Irwin, 2004).
The initial results of this survey couldnot have been more surprising: despiteexhibiting a near pristene disk, M31’shalo is full of substructure and pointsto a history of accretion and disruption(Ferguson, 2002). Figure 1 shows animage of M31, constructed from the
Figure 1. A multi-colour mosaicof the INT WFC survey of M31,
involving 165 individualpointings over 40 square
degrees of the sky. North is atthe top, and East is to the left
of this image. Metal poor/youngstars are coloured blue, while
metal rich/old stars arecoloured red. The (colour-
dependant) substructure isobvious, and surprising given
the pristene nature of theGalactic disk. The dwarf
galaxies Andromeda I & III arevisible at the bottom left of this
figure; the newly discovereddwarf spheroidal, AndromedaIX, is just visible at the top leftas a small blue dot. NGC 205is also visible in this figure, at
the right-hand side of the disk.
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References:
Bolton, A., Burles, S., Schlegel, D., Eisenstein,D., Brinkmann, J., 2004, AJ, 127, 1860.
is some 15 kpc long and Figure 2shows a cartoon of its location. Theprogenitor of this feature appears tobe the satellite galaxy NGC 205,although this awaits spectroscopicconfirmation. This object has long beenknown to be tidally perturbed (Choi,2002; Hodge, 1973) but it is only nowthat the full extent of its disruptionis becoming clear. Considerableamounts of other substructure existsin addition to these streams. Forexample, near the position of thefamous M31 globular cluster, G1, liesa large blue clump of stars (bottomright of Figure 1) and opposite thisacross the minor axis, near the positionof the famous HI warp, lies a redderone. The origin of both these featuresis currently undecided, as is the originof the curiously sparse cloud of starsat the far north of our survey region.
As well as these and many otherobvious substructures, the INT WFCis allowing the identification ofpreviously unknown globular clustersin the halo of M31 (Huxor, 2004).These include some of the most distantso far discovered, at projected radii of
~80 kpc. So far 14 have been found,including a whole new class of cluster,much sparser than typical globulars.These objects, of which threecandidates have currently beenidentified, are far less concentratedand have larger half-light radii thannormal, making their appearancefuzzy and diffuse. A colour image ofone of these objects, created from ourphotometry, is shown in Figure 3.The identification and quantificationof the globular cluster system providesyet another valuable handle on theaccretion history of this giant galaxy.
The other spiral in the Local Group,the Triangulum Galaxy (M33), hasalso been surveyed with the INTWFC (Ferguson, 2004b). The structureof this galaxy is striking in comparisonto M31. Figure 4 shows the distributionof stars in this object and the lack ofsubstructure is immediately obvious.It appears that not all spiral galaxyhaloes need look like M31, and itraises the question: is there such athing as a ‘ typical ’ stellar halo?
There is then the question of theM31 dwarf satellite galaxies, severalof which are visible in Figure 1. In
total, we now have INT WFCphotometry for all of M31’s satellitesvisible from La Palma. A threedimensional map of the Andromedasubgroup, created from ourmeasurements, is shown in Figure 5.The homogeneous nature of our datahas allowed accurate and internallyself-consistent distances andmetallicities to be measured for eachof these galaxies(McConnachie, 2004a,2004b). This allows us for the firsttime to reliably probe the threedimensional spatial distribution ofthese objects, revealing that far frombeing isotropically distributed andunbiased indicators of the potential ofAndromeda, there are strongindications that these objects arepreferentially located on the near sideof Andromeda, towards the Galaxy.This result is unexpected, andintriguing.
The INT WFC survey of M31 and itsenvirons has revealed, and continuesto reveal, startling surprises about thefaint surroundings of otherwise normalgalaxies. Its tendency to raise morequestions than answers seems to becontinuing, and it offers a warning tostudies of our own Galactic halo: givenour position inside the Galaxy, howwould we interpret our stellar halo ifit looks in the least bit like M31? ¤
Figure 2. Cartoon showing the path ofthe new stellar steam candidate, theprogenitor of which is thought to beNGC 205 (large red ellipse). Alsohighlighted are the location of severalfields being used to probe the kinematicsof the halo, as well as the dwarf ellipticalgalaxy M32. The stellar arc is some 15 kpcin length and may be able to shed lighton the dynamical evolution of NGC 205,and provide a useful probe of the potentialof M31. Although previously known tohave been tidally perturbed, this is thefirst detection of a probable significantextra-tidal component of NGC 205.
Figure 3. An example of a new class ofglobular cluster around M31, much sparserthan typical globular clusters, beingdiscovered by the INT WFC survey.Fourteen new globular clusters have sofar been discovered, many at largeprojected radii.Three of these objectshave morphologies similar to theabove.The half- light radii of these clustersare significantly larger than normal.Follow-up spectroscopic observationsshould yield important information as totheir true nature.
Figure 4. The spatial distribution of stellarsources in the INT WFC survey of M33,the Triangulum Galaxy. This is a smallspiral, approximately one-tenth the sizeof Andromeda. The lack of substructurein this galaxy is in startling contrast toM31 —virtually no spatial inhomogeneitiesare present in this galaxy’s outer regions.
McConnachie, A. W., Irwin, M. J., Ferguson,A. M. N., Ibata, R. A., Lewis, G. F.,Tanvir, N., 2004b, MNRAS, submitted.
McConnachie, A. W., Irwin, M. J., Lewis,G. F., Ibata, R. A., Chapman, S. C.,Ferguson, A. M. N., Tanvir, N. R., 2004c,MNRAS, 351, L94.
Searle, L., Zinn, R., 1978, ApJ, 225, 357.
White, S. D. M., Rees, M. J., 1978, MNRAS,183, 341.
Choi, P. I., Guhathakurta, P., Johnston,K. V., 2002, AJ, 124, 310.
Ferguson, A. M. N., Irwin, M. J., Ibata, R.A., Lewis, G. F., Tanvir, N. R., 2002, AJ,124, 1452.
Ferguson, A. M. N., et al., 2004a, in prep.
Ferguson, A. M. N., et al., 2004b, in prep.
Font, A., Johnston, K., Guhathakurta, P.,Majewski, S., Rich, M., 2004, AJ,submitted.
Hodge, P. W., 1973, ApJ, 182, 671.
Figure 5. The distribution of the satellite galaxies of M31, as derived from our INT WFC photometry of these objects. The coordinatesystem is an M31–centric system. The plane is the plane of the disk of M31, and each cell corresponds to 100kpc×100kpc. l isa longitude measured around the disk of M31, such that l =0 is the longitude of the Galaxy. b is a latitude, measured from the diskof M31. Solid lines indicate objects located above the plane of the disk, while dashed lines indicate objects below the plane of thedisk. A clear tendency for the satellites to lie on the near side of M31 can be observed, and suggests an intriguing correlation betweenthe M31 satellites and our own Galaxy.
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Huxor, A., et al., 2004, in prep.
Ibata, R., Irwin, M., Lewis, G., Ferguson,A. M. N., Tanvir, N., 2001, Nature, 412, 49.
Ibata, R., Chapman, S., Ferguson, A. M.N., Irwin, M. J., Lewis, G. F., McConnachie,A. W., Tanvir, N., 2004, MNRAS, 351, 117.
Irwin, M. J., et al., 2004, in prep.
McConnachie, A. W., Irwin, M. J., Ibata,R. A., Ferguson, A. M. N., Lewis, G. F.,Tanvir, N., 2003, MNRAS, 343, 1335.
McConnachie, A. W., Irwin, M. J., Ferguson,A. M. N., Ibata, R. A., Lewis, G. F.,Tanvir, N., 2004a, MNRAS, 350, 243.
The Bull’s Eye Pattern in the Cat’s Eye and OtherPlanetary Nebulae
Romano L. M. Corradi (ING)
red giant, the so-called theAsymptotic Giant Branch (AGB)stage. In the last million years of theAGB, the red giant is dynamicallyunstable and pulsates with typicalperiods of few hundred days: aprototypical star in this phase isMira in Cetus. The mechanicalenergy of the pulsations pusheslarge amounts of material far awayenough from the core of the star for itto cool down and condense into dust.
This newly formed dust is furtheraccelerated out of the gravitationalbounds of the star by the pressure ofthe radiation coming from the hotstellar remnant. Gas, which is coupledto dust by collisions, also leaves thestar in this process.
In the last hundred thousand yearsof the AGB, this mass loss process isso strong that the star is completelysurrounded by a thick, expanding
T he end-point of the evolutionof solar-type stars isessentially determined by
the onset of a strong stellar wind,which, in a few hundred thousandyears completely removes the star’sgaseous envelope, thereby removingthe fuel that has previouslymaintained the thermonuclearenergy source in its interior. Thisphenomenon occur during a (second)phase in which the star becomes a
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dust shell that makes it very difficultto observe what is going on inside it.One way to recover valuableinformation about this critical phaseof stellar evolution is to study theprogeny of AGB stars, i.e. planetarynebulae (PNe). These are nothing butthe ejected AGB envelopes, heated bythe radiation of the hot stellar core,and therefore emitting at the specificwavelengths (emission-lines) typicalof the gas that they are composed of.
PNe are fantastic laboratories in whichto study a variety of physicalphenomena, for example, in the pastmany aspects of atomic and molecularphysics have been addressed bystudying PNe. More recently, PNehave become laboratories forinvestigating the (hydro)dynamicalformation of shock waves produced bycollisions between stellar winds, withthe consequent formation of thingaseous shells, and bipolar flows orjets which closely resemble thoseobserved in other type of stars or inthe nuclei of active galaxies. Now weknow that if we understand theformation of the complex andspectacular shapes displayed by PNe,a lot can also be understood about thevery late AGB evolution. A few yearsago, we have in fact shown that a largefraction of PNe, perhaps the majority,are surrounded by large ionized haloes,one to ten thousand times fainter thattheir inner regions (Corradi et al.,2003). Figure 1 shows the halo of thewell-studied Cat’s Eye nebula (NGC6543); other examples of PNe haloescan be found in the ING NewsletterNo. 6, p. 35. These haloes are thefossil remnants of the strongest massloss phase during the AGB, their edgecorresponding to the last thermonuclearrunaway (helium shell flash) whichoccurred in a thin shell inside thestellar envelope before the star left theAGB. These shell flashes are also called“thermal pulses” and occur every100,000 years for a solar-like star. Inthermal pulse, mass loss from the staris first significantly enhanced, and thenquickly decreases. Therefore massloss during the AGB is modulated bythe thermal pulses, the last of whichleaves an observable signature in theedge of the PNe haloes (the gas lossduring the previous thermal pulses
Figure 1. Image of the Cat’s Eye Nebula obtained with the Nordic Optical Telescopeat La Palma. Rings (displayed in blue in order to better visualise them), are located inthe inner regions of the large filamentary halo of the nebula.
Figure 2. Image of Cat’s Eye obtained with the Advanced Camera for Surveys (ACS)of the Hubble Space Telescope. Image credit: ESA, NASA, HEIC and the HubbleHeritage Team (STScI/AURA). See also http://www.spacetelescope.org/images/html/zoomable/heic0414a.html.
has already diluted so much that ishardly detectable).
In 1999, HST images of the Cat’s Eyerevealed the presence of a series ofshells in the inner regions of its halo(Balick et al., 2001). They appearedto be produced by mass ejected fromthe star in a series of pulses at about1500 years intervals during the last20,000 years of the AGB evolution.Each shell contains about onehundredth of the mass of the Sun, i.e.approximately the mass of all theplanets in the Solar System combined.When projected in the sky, these shellsappear as “rings” (or sometimes “arcs”)composing a sort of “bull’s-eye” pattern.A new image of the Cat’s Eye, showingthe full beauty of the rings, was recentlyobtained with the ACS camera on theHST, and is displayed in Figure 2.
Discovery of these rings came as asurprise, as mass-loss modulation ona timescale of 1000 years was notpredicted by theory (compare with the100 times longer timescale of therecurrence of thermal pulses). First,it was thought that rings were a rarephenomenon, but recent observationstaken with telescopes at ESO and LaPalma, and mainly with the WideField Camera of the 2.5 Isaac NewtonTelescope, have instead shown thatthese structures are likely the rulerather than the exception (Corradi etal., 2004). They are thus of generalrelevance to understanding the largemass loss increase that characterisesthe end of the evolution of a star likethe Sun. Figure 3, left, shows examplesof these rings in three PNe; thesestructures are better highlighted byappropriate image processing (e.g.logarithmic derivatives or variationsof this method, as shown in Figure 3,right).
Several mechanisms have beenproposed for the formation of theserings. They include binary interaction(but the large detection rate weakensthis hypothesis), magnetic activitycycles, or stellar pulsations caused byinstabilities in the hydrogen burningshell inside the AGB envelope. Anotherpossibility is that gas is ejectedsmoothly from the star, and rings arecreated later on due to formation of
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Figure 3. Images of rings recently detected in PNe. Left: [OIII] images. Right: the sameimages processed to enhance the rings (Corradi et al., 2004, adapted from the A&Acover, April 2004 issue).
hydrodynamical waves in theoutflowing material that are causedby a complex coupling between gasand dust. This is an appealinghypothesis, as it comes out naturallyfrom our present knowledge of thephysics of the AGB mass loss. In anycase, whatever the correct explanation,it is clear that any AGB mass losstheory should now confront theevidence that these rings are frequentlyfound in PNe, and thus contain
important information relating to thevery late evolution of a large fractionof stars in the Universe. ¤
practical limitation for AO is theavailability of bright guide stars tomeasure the wavefront distortions,which has caused AO in general toproduce fewer science results than onemight have expected from its potential.By using an artificial laser guide starthis limitation is largely taken away,thus opening up AO to virtually allareas of observational astronomy andto virtually all positions in the sky.In particular, it opens up the possibilityof observing faint and extended sources,and will enable observations of largesamples, unbiased by the fortuitouspresence of nearby bright stars. Witha laser guide star facility, a 4-m classtelescope situated on a good observingsite like La Palma is highly competitivefor AO exploitation next to the largertelescopes. Examples of science areasthat may profit from the laser facilityare the search for brown dwarfs anddisks around solar type stars inobscured star formation regions,super-massive black holes, dynamicsof nearby galaxy cores, circumnuclearstarbursts & AGN, gravitationallenses, and physical properties ofmoderately high redshift galaxies.
Since January this year work startedon designing the various componentsof the laser beacon system. Althoughmaybe not a project of a very largescale, the complexity is quite significantand offers various challenges forengineers and astronomers alike. Theproject will be a joint endeavour with,besides ING, participation from theUniversity of Durham, the ASTRONinstitute in the Netherlands, theUniversity of Leiden, and the Institutode Astrofísica de Canarias. Below wewill set out the main components andchallenges of the laser system andsummarise the performance prospects.
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TELESCOPES AND INSTRUMENTATION
GLAS: A Laser Beacon for the WHT
René Rutten (Director, ING)
I n January 2004 the NederlandseOrganisatie voor WetenschappelijkOnderzoek (NWO) announced its
full support for the proposeddevelopment of a laser beacon for theNAOMI Adaptive Optics (AO) systemon the 4.2-m William HerschelTelescope (WHT). Such a laser guidestar system will amplify the fractionof sky available to AO observationsat visible and infrared wavelengthsfrom about one percent to nearly 100%.In terms of astronomical research,this translates into radical progressas it opens up high spatial resolutionobservations from the ground to nearlyall types of science targets. Incombination with the existing andplanned instrumentation, the WHTwill offer a highly competitive facilityto the astronomical community,exploiting a window of opportunitybefore similar capability will exist on8-m class telescopes.
AO techniques allow ground-basedobservers to obtain spatial resolutionsbetter than a tenth of an arcsecond bycorrecting the image blurringintroduced by the Earth’s atmosphere.Hence the resulting image sharpnessnot only carries the advantage ofdistinguishing finer structure andavoiding source confusion in densefields, but it also allows observationsto go significantly fainter, as the skybackground component reduces withthe square of the angular resolution.For these reasons, AO instrumentationis being planned for nearly all largetelescopes, and it is at the heart ofthe future generation of extremelylarge telescopes.
At the WHT, AO recently came tofruition with the commissioning ofthe common-user AO system, NAOMI,and an aggressive instrumentdevelopment programme. A main
Figure 1. The Durham laser experimentin action at the WHT in April 2004.
Laser Guide Stars Basics
The idea is simple: a laser beam isused to generate a point source ashigh as possible in the sky, projectedtowards the same area as where thetelescope is pointing. That laser beaconilluminates the atmospheric turbulenceabove the telescope and is used forsensing the corrugation of the wavefrontcaused by that turbulence. The higherthe laser beacon is projected thebetter it is, as in that way it bestapproximates a source from infinity.
There are basically two ways toproduce a laser beacon: eitherexploiting a layer of relatively highsodium density in the atmosphere atsome 90 km, or ‘just’ using back scatterin the atmosphere. The sodium laseroption is technologically verydemanding for reason of lasertechnology and for the implications ithas on the design of the AO system.The Rayleigh laser, however, issomewhat easier as it can use existingoff-the-shelf laser technology which isalso much less expensive and easierto maintain. The Rayleigh has howeverthe disadvantage that the beacon willat best be at an altitude of some 20 km.The lower elevation implies thatatmospheric turbulence very high inthe atmosphere will not (properly) besensed. Turbulence close to observatorywill be well measured, and thereforeit is often referred to as ground-layerAO. This feature has given the nameto the laser project for the WHT: GLAS,for Ground layer Laser Adaptive opticsSystem (or better in Dutch, GrondlaagLaser Adaptieve optiek Systeem).
Evidence built up over the yearsindicate that ground-level turbulenceoften dominates, a nice example ofwhich is shown in the paper in thisNewsletter by García et al. Over thenext several months more solidexperimental data will be gatheredabout the turbulence characteristics.
System Overview
First of all, the Rayleigh laser systemis designed to work in conjunctionwith existing AO equipment (NAOMI)and its ancillary instrumentation and
infrastructure like the INGRID IRcamera and the OASIS integral-fieldspectrograph. A powerful 25 to 30Wpulsed laser will be focussed to some20 km altitude from a launch telescopemounted behind the secondary mirror.The pulse will produce a short (tensof meters) column of light that travelsthrough the atmosphere. The Rayleighback scattered light from this pulsewill find its way back to the telescope.About 10% of all the light is scatteredinto the atmosphere, but of course inall directions and along the full depthof the atmosphere. Only a very smallfraction of the laser light returns tothe telescope and can be used to sensethe turbulence, hence the need for apowerful laser in order to produce abeacon that is bright enough to servefor AO.
Only photons returning from a certainset altitude range are useful to us.Hence unwanted photons have to beblocked from entering the detector.This will be done using a combinationof a geometric filter that will obstructmost of the unwanted light, and a veryfast electro-optical Pockels cell shutter.The timing of this Pockels cell shutteropening will be slaved to the laserpulse signal, and open exactly whenthe Rayleigh scattered light from analtitude of 20 km returns to thetelescope. The very short period during
which the shutter remains open setsthe length in the atmosphere overwhich the laser beacon will extend.
Having passed the shutter, theRayleigh back-scattered light will bedetected by a wavefront sensor systemthat measures the instantaneouswavefront shape from the laser guidestar. The results from thismeasurement, some 300 times persecond, will provide the demandedshape that the deformable mirror of theAO system will have to take in orderto correct for the wavefront corrugation.
So far the situation is very similar toa ‘standard’ natural guide star AOsystem, except that laser light is usedrather than light from a star. However,as the laser light travels through theatmosphere twice along more or lessthe same path, the measured wavefrontdoes not contain information on theoverall image shift (tip-tilt) caused bythe atmosphere. Hence to measure thetip-tilt component still a natural guidestar is required, but such star can bequite faint and may be relatively faraway from the science object.
The existing wavefront sensorsystem will be dedicated to tip-tiltmeasurements on a star. Therequirement for having such star nearthe science object still poses a
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Figure 2. System diagram for the GLAS and NAOMI system.
limitation on the effective sky coverage.To maximise our chances of finding asuitable star even more, the existingwavefront sensor will be upgradedwith a Low-Light-Level CCD that hasvirtually zero read noise and wouldgive us an extra magnitude in faintestdetectable star. As can be seen in theadjacent figure (courtesy Remko Stuik,Leiden) the conservatively estimatedsky coverage will be extremely good,even at the galactic pole.
The laser light scattered into theatmosphere of course has to be blockedfrom entering the science instruments,both at the WHT as at other telescopesat the observatory. Within NAOMI adichroic mirror will block the laserlight from going into the science beam.But the situation with other telescopesis more complicated and requires acoordination of laser operation andthe pointing of all telescopes thatmight be affected in order to avoidthat some telescope will inadvertedlycross the laser beam. Much experiencewith this problem has been obtainedat Mauna Kea observatory wheresuch a laser traffic control systemhas been put into operation. A similarsystem will be put into operation atLa Palma. The system will collectpointing information and inform alltelescopes whether or not there is arisk of crossing the laser beam. Ifnecessary the laser beam willautomatically be intercepted.
Performance Expectations
In preparation for this project, variousperformance predictions were carried
out by Richard Wilson at DurhamUniversity. As the main scientificniche for AO at the WHT rests withthe visible light OASIS integral-fieldspectrograph the focus is on achievingmoderate but significant improvementsof image quality down to 0.6nm. It isunrealistic with current technology toaim for high Strehl ratios at thesewavelengths. But as the calculationsbelow show, image FWHM will improvevery significantly at short wavelengthsand performance in the near IR iseven better.
The model calculations were designedto deliver realistic figures for theexpected improvement of image qualityas a function of seeing, wavelength,natural guide star brightness, anddistance of the natural guide star tothe science object. A typical profile ofatmospheric turbulence strength withheight was assumed. The followingtable shows a few of the model results.The model calculations indicate veryattractive improvements in imagequality when NAOMI will be usedwith a laser beacon. But of courseabove all, the laser enhancement willprovide such performance for nearlyany point in the sky, thus opening upthe exploitation of AO to surveys oflarge number of targets.
Scientific Invitation
The GLAS project will open up a newexciting area of astronomicalexploitation for the William HerschelTelescope. There is much work ahead,and much to learn on how to optimallyuse the future new facility. Moreover,an added attraction of the laser systemis that it can serve as a testbed forconcepts of future laser systems atmuch larger telescopes.
Progress on this project will be reportedin future articles in this Newsletter.If you are excited about the prospectsas we are, and interested in workingwith us to define detailed scientificplans, don’t hesitate to contact us. ¤
Figure 3. Representation of the skycoverage for finding a star brighter thanR=18 within a search diameter of 1.5arcminutes (courtesy Dr Remko Stuik,Leiden University).
Cute-SCIDAR: An AutomaticallyControlled SCIDAR Instrument for theJacobus Kapteyn Telescope
J. J. Fuensalida1, B. García-Lorenzo1, J. M. Delgado1,C. Hoegemann1, M. Verde1, M. Reyes1 and J. Vernin2
1: Instituto de Astrofísica de Canarias; 2: Laboratoire Universitaire d'Astrophysique de Nice
to be the most contrasted and efficienttechnique from ground level to obtainthe optical vertical structure of theatmospheric turbulence. The classical(Vernin & Roddier, 1973; Rocca,Roddier & Vernin, 1974) andgeneralised SCIDAR (see e.g. Klueckerset al., 1998; Ávila, Vernin & Masciadri,1997; Fuchs, Tallon & Vernin, 1994)techniques analyse the scintillationpatterns produced at the telescope
I n February 2004 the Cute-SCIDAR instrument was installedat the 1m Jacobus Kapteyn
telescope (JKT) for a systematicmonitoring of the atmosphericturbulence at the Observatorio delRoque de los Muchachos (ORM). Theproper knowledge of the atmosphericturbulence structure is crucial foroptimising the efficiency of adaptiveoptics systems. SCIDAR has proved
is lodged in two devices permittingthe motion in the XY plane(perpendicular to the optical axis) tocorrect the small flexure displacementsin the observational plane. Themaximum range in the XY plane is25mm. A long electronically controlledrail to place the detector in theadequate conjugated plane providesthe movement along the optical axis,Z direction. This motion also facilitatesthe instrument focusing procedure,since it permits to easily verify (usinga single star) the state of collimationof the beam. The maximumdisplacement in the Z direction is300mm. The current detector is acommercial sensitive CCD camera ofPCO. The instrument can rotate upto 270° with respect to the telescopethrough a crown wheel. Anothercomplementary mechanism is adiaphragm, placed in the focal planeof the telescope (see the scheme ofFigure 2), and also electronicallycontrolled. The diaphragm mechanismpermits the proper alignment of theobserving binary star with theinstrument optical axis. After a shortsuccessful commissioning at the CarlosSánchez telescope at the Observatoriodel Teide in Tenerife, the Cute-SCIDARwas installed at the JKT in February2004. Figure 3 (left) shows the Cute-
SCIDAR already installed at the JKT.Figure 3 (right) shows the essentialinstrument components. In this figure,we can see the diaphragm andcollimator (1) within the instrumentcover. The detector can be seen at thebottom opened door (2) and the crownwheel is the golden ring (3) connecting
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Figure 1. SCIDAR technique layout. From the observation of binary stars, we get astack of consecutive images of scintillation. The average auto-correlation function ofthem gives information of the CN
2 profiles, and average cross-correlation functionsgive the wind of the layers.
Figure 2. SCIDAR instrument opticalscheme.
pupil by the light coming from thetwo stars of a binary system.Turbulence profiles as a function ofheight, CN
2 (h), are derived throughthe inversion of the autocorrelation ofscintillation patterns. Wind verticalprofiles, V(h), are derived from thecross-correlation of a series ofscintillation patterns relative to areference pattern. Figure 1 sketchesthe SCIDAR technique.
The main drawback of SCIDARobservational campaigns is the tedioussetting up of the instrumentation andthe computational effort needed toinfer the nightly turbulence and windprofiles. Therefore, systematicrecording of turbulence and windstructure requires a huge number ofhighly qualified human resources.Consequently, the development of afully automated SCIDAR device is ofincreasing importance to characterisethe atmospheric turbulence and fixthe input requirements and limits ofthe future multi-conjugate adaptiveoptic systems to be installed at theORM. The Instituto de Astrofísica deCanarias (IAC) has developed aSCIDAR instrument providing highperformance in automatic control anddata reduction, the Cute-SCIDAR. Ithas been designed for the 1m JKT,with the goal of monitoring the verticalturbulence with a high temporalcoverage. This device is not onlyrestricted to the JKT but can also beused on other telescopes.
Technical Description
Figure 2 presents the optical schemeof the SCIDAR instrument. From theobservational point of view, theSCIDAR technique requires that thedetector is able to move along theoptical axis to allow selection of thedifferent conjugated planes. Moreover,the rotation around the optical axisis most than desirable for a SCIDARinstrument: because the star beamsshould be properly orientated on thedetector (with its rows) in order tosimplify the data reduction.
The Cute-SCIDAR allows theautomatic control of any of the SCIDARinstrument components. The detector
the instrument and the telescope. Thelabel (4) indicates the electronic boxcontrolling the mechanical elementsof Cute-SCIDAR.
Control Software
A specific software package for thecontrol of the different mechanicalcomponents and a pre-processing on-line data evaluator has been developed.A user-friendly interface based onMS-WINDOWS XP allows handlingthe different instrument componentsfrom the telescope control room.Figure 4 shows an example of thequick-look data interface: the leftupper image corresponds to the pupilimage of a binary star (the datarecorded at the detector), and theright upper plot is the 2D normalisedauto-correlation of this image; thebottom plots are cross-correlations ofthe left upper image and a referenceimage. The bottom right plot is a X-cut along the 2D autocorrelationfunction showing the presence of atleast two turbulence layers (the twopeaks to the left and right of thecentral brightest peak).
Observational Campaignsat the JKT
After a successful commissioning ofthe Cute-SCIDAR at the JKT lastFebruary 2004, we have started amonitoring program of theatmospheric turbulence. We arecarrying out monthly one-weekobserving SCIDAR campaigns andwe already have data correspondingto 30 nights of observations. On eachnight we can record more than 1500different atmospheric turbulencevertical profiles above the Observatoriodel Roque de los Muchachos.Preliminary results obtained fromthese data have been recentlypresented to the astronomicalcommunity (Fuensalida et al., 2004;Hoegemann et al., 2004; Fuensalidaet al., 2003). Figure 5 shows thetemporal evolution of the atmosphericturbulence profiles along an observingnight at the JKT. In this figure, theX-axis corresponds to the time (in UT)along the night referred to midnight.
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Figure 3. Views of the Cute-SCIDAR instrument installed at the Jacobus KapteynTelescope.
Figure 4. User interface window showing an example of the on-line data evaluator.
Figure 5. Evolution of turbulence vertical profiles at the Observatorio del Roque delos Muchachos during the night of 23-24 April 2004. The mean seeing derived fromthese profiles was 0.84 arcsec being in good agreement with the DIMM measurements.
The Y-axis is the altitude above sealevel, and the colour bar on the rightside indicates the values of CN
2(h).The dome seeing contribution hasbeen rejected.
In semester 2004B we will continuethe monitoring of the turbulencestructure at the JKT after theextension of the agreement with theIsaac Newton Group of Telescopes.The Cute-SCIDAR team thanks thestaff of the Isaac Newton Group ofTelescopes for their usual highstandard of service. ¤
Fuensalida, J. J., Chueca, S., Delgado, J.M., García-Lorenzo, B., González-Rodríguez,J. M., Hoegemann, C., Mendizábal, E.M., Reyes, M., Verde, M., & Vernin, J.,“Vertical structure of the turbulence inthe observatorios of the Canary Islands:parameters and statistics for adaptiveoptics”, Astronomical Telescopes andInstrumentation: The industrial revolutionin Astronomy, SPIE Proc., 21-25 June2004, Glasgow, Scotland United Kingdom.
Fuensalida, J. J., Delgado, J. M., García-Lorenzo, B., Hoegemann, C., Reyes, M.,Verde, M., & Vernin, J., “An automaticallycontrolled SCIDAR instrument for theRoque de los Muchachos Observatory”,Second Workshop on Extremely LargeTelescopes, SPIE Proc., September 7-122003, Backaskog, Sweden.
Fuchs, A., Tallon, M., &Vernin, J., 1994,SPIE Proc., 2222, 682.
Hoegemann, C., Chueca, S., Delgado, J.M., Fuensalida, J. J., García-Lorenzo,B., Mendizábal, E. M., Reyes, M., Verde,M., Vernin, J., “Cute SCIDAR: presentationof the new Canarian instrument andfirst observational results”, AstronomicalTelescopes and Instrumentation: Theindustrial revolution in Astronomy, SPIEProc., 21-25 June 2004, Glasgow, Scotland,United Kingdom.
Council (PPARC) provided some seedfunding for SuperWASP, the bulk ofthe funding came from the Queen’sUniversity Belfast (QUB). Othercontributions came from the OpenUniversity, the Royal Society, AndorTechnology and St. AndrewsUniversity. The QUB funding becameavailable in March 2002.
Those of you who have been out to LaPalma over the last year may havenoticed the appearance of theSuperWASP enclosure on the Roque.In fact avid viewers of the CONCAMall-sky images noticed that thebuilding was erected during the dayof the 6th July 2003. Shaped like agarage sized shoe box but with apeculiar stepped-roof, it is sited on thehillside below the JKT towards theSwedish Solar Telescope. The enclosureis composed of two rooms with theinstrument itself located at thesouthern end of the building and thecontrol computers at the other end.
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SuperWASP: The Trials and Tribulationsof a Remote Inauguration Ceremony
Don Pollacco (Queen’s University Belfast), Ian Skillen (ING),Javier Méndez (ING) and the WASP Consortium
I t is ironic that in this technicalage we live in there are fewprofessional facilities in operation
that are designed to monitor the skyat optical wavelengths. Historically,this work has been left to dedicatedamateur astronomers often usingobservatory grade equipment. Part ofthe reason for the absence ofprofessional projects is the lack ofreliable equipment and the huge datarates involved. The SuperWASPfacility is an attempt by professionalsto join in the exploitation of the timedomain. It is the rapid developmentof robotic technology and affordable,but powerful, computing that hasmade this project feasible.
The main science aims of SuperWASPinclude the detection of extra-solarplanets (the so-called hot-Jupiters),optical counterparts to Gamma-RayBursters and rapidly moving near-Earth asteroids. While the UK ParticlePhysics and Astronomy Research
Figure 1. SuperWASP at dusk on the 27th November 2003 — first light. The WHT domeis in the background (photo courtesy Jens Moser).
The computer room is protected by atelecommunications grade airconditioning plant. The detectorsthemselves are the 2048×2048 pixele2v42 CCD devices familiar to WHTusers, but are thermo-electricallycooled. The optics are the now obsoleteCanon 200mm F1.8 telephoto lenses,often described as “the fastest telephotolens available”.
After obtaining planning permissionon La Palma, construction of thefacility began in June 2003. In July,we erected the enclosure using probablythe most highly qualified labourersavailable (and the worst paid ! )followed by the associated electricaland communications work. By mid-August we installed the fork mountand built up the computer systems.By September 2003 we had completedthe first pointing models with themount and started to build up thecamera cradle —initially with 4detectors included. Engineering firstlight occurred late in the month. Aftera break for engineering work (and togive a lecture course) true astronomicalfirst light occurred in late November2003 — some 21 months after thefunding became available. SuperWASPthen regularly obtained data up untilChristmas. We had a scheduled breakfor three months to address some ofthe many technical issues highlightedfrom our operational month, as wellas to re-engineer some of the cameraheads. The data from that period hasproved invaluable in debugging thereduction pipeline prior to
commencement of normal operationsscheduled for mid-April 2004.
As is common with new instrumentswe decided to hold an inaugurationceremony for the facility and it seemedlike a good idea to hold this event atthe start of operations on Friday 16th
April 2004. However, as the dateapproached and with the detectorsstuck with DHL in Madrid for severalweeks (they arrived there a few daysafter the tragic terrorist attacks), webecame more concerned that we maybe forced to inaugurate the facility withjust the single detector left on LaPalma. Just to compound our problems,the weather on the Roque had beensomewhat unpredictable with a severecold spell. After several interventionson our behalf by various bodies, thedetectors finally arrived back on theRoque on Monday 12th April,whereupon we built up the cameracradle. By Wednesday the weather hadturned worse with a blizzard layingsome 10 cm of snow overnight. At 3 pmthe day before the inauguration wasdue to take place we took the decisionto abandon the event at the summit,and after some discussion, to hold theevent at the ING sea-level base. TheIAC representatives rearranged thepress and other official matters, andat the same time we rearranged thesocial activities.
Tests Thursday morning had shownthat, in principle, provided the networktraffic wasn’t too high, we could runSuperWASP remotely from sea level.
THE ING NEWSLETTER No. 8, September 2004
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During normal operations the roofabove the instrument slides, underhydraulic pressure, onto the computerroom end, and the cameras are exposedto the sky. The SuperWASP camerasare contained within a cradle andmounted in place of a telescope tubein an equatorial fork mount.
Compared to, for example the INTWide Field Camera, the field of viewof SuperWASP is truly awesome:currently about 1200 times larger. Toachieve this SuperWASP is composedof five cameras each having a dedicatedtelephoto lens and CCD detector. Thelenses image onto the detector at lowangular resolution (14 arc secondsper pixel) hence allowing a large fieldof view for the camera. This designallows us to achieve accuratephotometry on bright objects (<1%for stars brighter than magnitude 13for a single 30 second integration).However, with such large angularpixels the sky level is quite brightwhich limits the magnitude of objectsdetected (3σ detection at magnitude16.5 per 30 second integration).SuperWASP is able to accuratelymeasure the brightness of millions ofstars in a single night.
The equatorial mount, along with theobservatory control software, TALON,is the heart of SuperWASP. TALONcontrols all observatory functions(e.g. monitoring the weather station,GPS time service, etc.), as well asindirectly controlling all CCD camerasvia their data acquisition computers.
Figure 2 (left). First light mosaic image of the southern part of Orion. In this 1 second exposure the horse head nebula andBarnard loop are clearly visible along with some 35,000 stars.
Figure 3 (right). A two chip mosaic of Comet Neat on 15th May 2004 (courtesy of Alan Fitzsimmons). Wow!
Thursday afternoon we reconfiguredthe observing system to includestreaming video from our internalnetwork camera as well as a view of thebuilding from our external camera.SuperWASP had always been designedto be able to be run in this way, butthe weather conditions had forced usto attempt this operational modeseveral months before we expected to.We were surprised it worked so well !For the inauguration we would attacha red ribbon to the camera cradle whichwould (in principle) fall to the groundas the instrument was moved. At thistime our UK based guests were alsoarriving, including Professor KennyBell (Pro-Vice-Chancellor at QUB) andProfessor Martin Ward (Chair of thePPARC Science Committee).
Surprisingly the weather on the Roqueon the day of the inaugurationceremony stayed fair but cold. Withthe remnants of the snow still aroundand some ice still on the road we feltvindicated in our decision to move tosea level. The event itself went almostexactly to plan, culminating with theMayor of Garafía moving the camerasand the ribbon falling. This was justas well: there was no reserve plan, nopre-recorded videos of the instrumentrunning. The only slight (well amusing)flaw occurred when after the ceremonythe TV cameras asked to repeat thefinal part of the ceremony during whichthe ribbon stubbornly refused to falluntil discreetly helped! Ironically theweather had forced us to remotelyinaugurate a robotic instrument —afirst as far as we are aware, and mostsatisfying given the adverse conditionswe faced at the time.
SuperWASP has now moved into theoperational phase. At the time ofwriting the facility is runningautomatically but not yet robotically.During normal observing SuperWASPtakes 30 second integrations whichafter allowing for readout and telescopemovements results in, on average,about one integration every 60 seconds(for each camera). Each detectorproduces an image of 8.3MB in size,hence an average night with thecurrent system results in about25–30GB of science and calibrationdata. At the end of the night this is
written to DLT tape and shipped backto QUB for analysis. After reductionthe brightness measurements arestored in a database hosted (andfunded) by Leicester University(LEDAS). We are currently gainingvaluable information on how to runthis instrument efficiently with aview to running a limited (attended)robotic mode in late 2004.
New funding, obtained by Keele andSt. Andrews Universities, will allowthe full expansion of SuperWASP (8camera units giving a field of view ofsome 500 square degrees), as well asthe construction of a clone facilitydestined for SAAO. In thisconfiguration SuperWASP will beable to image the available part of the
celestial sphere in only 67 pointings(with these optics), while the visiblesky can be surveyed in less than 40minutes. Thus SuperWASP canefficiently monitor the whole sky. Donot be deceived: it may be small butit’s powerful !
The WASP Consortium is composedof astronomers from the UKUniversities of Belfast, Cambridge,Keele, Leicester, Open, St. Andrewsas well as the IAC and ING. We areindebted and grateful to the staff ofboth the IAC and ING for theirenthusiasm and support for thisproject, and look forward to a fruitfulcollaboration in the months andyears ahead. ¤
Figure 4. A moment of the remote inauguration ceremony of SuperWASP on 16th
April 2004 from ING’s sea-level office in Santa Cruz de La Palma.
WHT Auto-guider/TV Upgrades
Simon Tulloch (ING)
advantages with regard to sparesand maintainability.
The new heads can be loaded withtwo kinds of detector which are pin-compatible, differing only in theirnumber of pixels. The small formatheads contain a CCD5710 which hasan image area of 512 ×512 ×13 µmpixels. The larger format heads use a
D uring the last year the ageingRGO auto-guider heads havebeen gradually phased out and
replaced with new higher performancecameras. These new cameras use ex-science camera SDSUII controllersfreed up in the wake of restructuringand the same data acquisition system(UltraDAS) used by the sciencecameras. This gives considerable
THE ING NEWSLETTER No. 8, September 2004
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CCD4720 with an image area of1024×1024 ×13µm pixels. The CCDswere supplied in hermetically sealedpackages with integral Peltier coolerswhich should improve reliability (theprevious heads required a continuousdry nitrogen flush to preventcondensation forming on the detector).The Peltier cooling reduces detectordark current to well below 1e– persecond. Heat from the Peltier deviceis dissipated in a finned heat sinkthat is force cooled by two small fanslocated within the head. The CCDsare mounted onto a small circuit boardthat provides pre-amplification of thevideo signal as well as static protection.Even when connected to theircontrollers through a 2.5m cable, aread noise of 4 – 5e– is obtained,similar to the level of the sciencecameras. The detectors are thinnedbackside-illuminated with mid-bandAR coatings that give QEs of >90%at 600nm.
These in-house designed cameras willeventually replace the Cryocam TVsystems also. As they use FrameTransfer CCDs they will be morereliable than the mechanicallyshuttered Cryocams. Their smallerformat, however, means that a focalreducer must be used to obtain thesame field of view and allow them toview the entire ISIS slit. A replacementfor the TV scale 12 slit viewing opticsbarrel is currently under constructionand should be delivered in September2004. Once installed at this stationthe new TV camera will also be capableof slit-guiding. Its images can also bearchived in FITS format with fullheaders to accompany the spectroscopicimages obtained with ISIS.
Figure 1. Left: the Auto-guider/TV hardware: Head, Controller and PSU rack. Middle: small format detector mounted on its PCB.Right: the complete Auto-guider/TV head.
Five cameras are now currently inuse at the following WHT stations:CASS Auto-guider, PFIP Auto-guider,AF2 TV, INTEGRAL Auto-guider,NAOMI Acquisition TV, NAOMISimplexing Camera. Stations still tobe filled are: CASS TV (awaiting newoptics) and Integral TV (awaiting newhead). Two more heads will be built;we already have the detector for thefirst of these.
The cameras are controlled primarilythrough dedicated GUIs where theauto-guiding and TV operations canbe controlled by the click of a mouse.Alternatively the user can use thestandard uDAS syntax to set upwindows and do runs in the normalway. Below is a selection of imagesobtained using these cameras duringthe commissioning phase. ¤
I saac Newton Group staff from both the astronomy and engineering groups hadseveral papers accepted by SPIE (The International Society for Optical Engineering)for their conference ‘Astronomical Telescopes and Instrumentation –The Industrial
Revolution in Astronomy’ held from 21 to 25 June 2004, at the Scottish Exhibition andConvention Centre in Glasgow. The range of topics reflected the range of developmentinterests at ING, many of the papers being about various aspects of adaptive optics. Thefull list of papers featuring ING staff is below, all but one of them having ING staff asprincipal author. At the conference Chris Benn and Simon Tulloch gave oralpresentations, while the remaining papers were poster presentations.
Papers given as oral presentations:
– “NAOMI: adaptive optics at the WHT”. C. R. Benn, S. Els, S. Goodsell, T. Gregory, A. Longmore1, R. M. Myers2, R. Østensen,I. Söchting4, G. Talbot.
– ”The application of L3 technology to wavefront sensing”.(http://www.ing.iac.es/~smt/)S. M. Tulloch.
Papers given as poster presentations:
– ”Advances in telescope mirror cleaning”.(http://www.ing.iac.es/~mfb/ing/ing.htm)M. F. Blanken, A. K. Chopping, K. M. Dee.
– ”An improved mechanism control system for INGRID”.(http://www.ing.iac.es/~sgr/poster.pdf)S. G. Rees, P. Jolley, M. van der Hoeven, A. W. Ridings, M. F. Blanken.
– ”GRACE: a controlled environment for adaptive optics at the William Herschel Telescope”.(http://www.ing.iac.es/~rgt/poster.html)G. Talbot, D. C. Abrams, C. Benn, A. Chopping, K. Dee, S. Els, M. Fisher3, S. Goodsell,D. Gray, P. Jolley.
– “Modelling the system performance and the final image PSF”. I. K. Söchting4, R. M. Myers2, C. R. Benn, A. J. Longmore1, R. Wilson2, S. Els, S. Goodsell,T. Gregory, R. Østensen, G. Talbot.
– ”Photon counting and fast photometry with L3 CCDs”.(http://www.ing.iac.es/~smt/)S. M. Tulloch.
– ”Recent enhancements to the NAOMI AO system”.(http://www.ing.iac.es/~jolley/SPIE.html)P. D. Jolley, S. Goodsell, C. Benn, T. Gregory, S. G. Rees, M. van der Hoeven, M. F.Blanken, R. Pit, C. Bevil.
– “The real time control system of NAOMI”.S. J. Goodsell, R. M. Myers2, D. Buschell7.
– “WHT auto-guider/TV upgrades”.(http://www.ing.iac.es/~smt/)A. W. Ridings, S. M. Tulloch, R. A. Bassom.
Papers given as poster presentations with ING co-authors:
– “AO-assisted integral field spectroscopy with OASIS”.R. McDermid5, R. Bacon6, G. Adam6, C. Benn.
1: UK Astronomy Technology Centre; 2: University of Durham; 3: Fisher AstronomicalSystems Engineering; 4: ING and University of Oxford; 5: Leiden Observatory; 6: Observatoirede Lyon; 7: University of Cambridge.¤
ING Papers for SPIE’s AstronomicalTelescopes & Instrumentation Conference
Seminars Given at ING
Visiting observers are politely invited to give a
seminar at ING. Talks usually take place in
the sea level office in the afternoon and last
for about 30 minutes plus time for questions
afterwards. Astronomers from ING and other
institutions on site are invited to assist.
Please contact Danny Lennon at
[email protected] and visit this URL:http://www.ing.iac.es/Astronomy/
science/seminars.html, for more details.
These were the seminars given in the last 10
months:
Dec 3. Arto Järvinen (NOT), “CCD RonSuppression Technique for EchelleSpectroscopy”.
Feb 3. Dr Dehua Yang (Nanjing Institute ofAstronomical Optics and Technology),“LAMOST Telescope and Instrumentation:Concept, Technologies and progress”.
Feb 20. Hugo E. Schwarz (CTIO-NOAO-AURA), “Circumstellar Matter in PNe andOther Evolved Stars”.
Mar 4. Silvano Desidera (PadovaObservatory), “Search for extrasolarplanets with SARG”.
Mar 12. Laura Magrini (Dipartimento diAstronomia e Scienza dello Spazio,University of Firenze), “Planetary Nebulaein the Local Group”.
Apr 6. Amir Ahmad (Armagh Observatory).“Helium-rich subdwarf B stars: binaries,mergers or bizarre?”.
Apr 7. Don Pollacco (QUB), “SuperWASP:The Super Wide Angle Search for Planets”.
Jul 2. Phil Charles (University ofSouthampton). “SALT: 6 months to go!”.
Jul 7. Suzanne Aigrain (IoA, Cambridge),“Planetary transits and stellar variability”.
Jul 30. P. Focardi (Dipartimento diAstronomia, Università di Bologna), “What’sthe role of environment on galaxies?”.
THE ING NEWSLETTER No. 8, September 2004
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Integral-field spectroscopy andadaptive optics (AO) techniques arecoming of age. A number of
integral-field spectrographs are inoperation around the world, and AOinstruments are proliferating andbecoming a standard feature of inparticular the largest ground-basedtelescopes. The combination of integral-field spectrographs and AO is still arelatively unexplored area where thepotential benefits for astronomy are huge.For that reason, a number of projectsare under way that will take advantageof the most recent technologicaldevelopments in these areas.
The advent of a new facility instrumentat the 4.2-m William HerschelTelescope, the OASIS Integral FieldSpectrograph, working in conjunctionwith the NAOMI Adaptive Opticssystem has prompted this initiative forholding a workshop covering this area.Moreover, a laser guide star facility iscurrently under development, whichwill open up nearly the full sky to AOexploitation. This implies a huge newpotential for AO assisted spectroscopyto be carried out on large samples ofobjects, as there no longer will be therestriction of having to have a nearbybright guide star.
The workshop will focus on thescientific achievements and prospectsfor AO-assisted integral-field spectroscopy,promoting discussion and sharing ofexperiences and ideas. The outcomecould inspire new collaborations andideas for observing programmes, whileat the same time it would provide theobservatory with scientifically inspiredadvice on how to maximally exploit theexciting possibilities of AO at theWillam Herschel Telescope.
The workshop will be held from 9–11May 2005 in Hotel H10 TaburientePlaya at Los Cancajos, La Palma. Forfurther details see the workshop webpages at: http://www.ing.iac.es/conferences/aoworkshop/. ¤
Workshop on Adaptive Optics-Assisted Integral-FieldSpectroscopy
Other ING Publications and Information Services
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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/
No. 8, September 2004 THE ING NEWSLETTER
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News from the Roque
T he 10-m GTC project is making visible good progress. As can be seen from theweb cameras on the GTC’s web page the telescope mount has been completed,
and the telescope structure itself is being mounted inside the dome. At the time ofwriting the mirror support cell is already completed. The first mirror segments havebeen received, as are the first instrument components such as the aquisition andguiding units and the commissioning camera. First light for this telescope is comingcloser !
The large Cherenkov telescope, MAGIC, is nearly fully operational. All mirrors havebeen fitted, providing for an impressive sight at night as well as during the day.First detections have already been registered early in the year. The ‘CountingHouse’ has been constructed close to the telescope, also containing a dome that willhost a small telescope used for calibration purposes. Furthermore, advanced plansexist for the construction of a second telescope of similar characteristics as MAGIC-1 and will be placed in the same area.
The SuperWASP (Wide Angle Search for Planets) project is now fully operational andhas been collecting data already for several months, but still under the watchful eyeof an observer. The telescope was inaugurated very appropriately in a remotefashion in April. The system has operated throughout summer in an automaticfashion. Later this year the telescope is expected to start full robotic operation andbe fitted with the full complement of 8 cameras.
The Liverpool telescope has had its first robotic observations earlier in the year.Following an upgrade to the hydraulic system for the enclosure the telescope willbe ready for full operation.¤
Top: MAGIC telescope and GTC (photocourtesy Francesca Phillips). Bottom:SuperWASP.
Personnel Movements
Andy Hide returned to the UK unfortunately only after having spent just over a year with ING as Head of the Telescope andInstrument Group. Andy’s vacancy has been filled by Diego Cano, who joined ING in September.
After many years at ING Doug Gray also decided to returned to the UK. It will be particularly difficult to replace his vastknowledge and experience of the infrastructure that is key to ING.
Juerg Rey, who was until recently heading the group of Telescope Operators, has assumed the role of Duty Head of theOperations Group, while Juan Carlos Guerra has brought the Telescope Operator Group back up to strength again.
In the software group Stephen Goodsell decided to take up a position at Durham University to work on adaptive optics relatedprojects and to progress his PhD. Vacant positions in the software group, some related to new development projects have beenfilled by Niko Apostolakos, Jure Skvarc and Sergio Pico.
Betty Vander Elst assisted the Administration group for some time on a part-time basis, but left ING during spring of this year.
Also the Astronomy Group has seen significant changes. Support Astronomers Almudena Zurita and Paco Prada, as well asMarco Azzaro (Telescope Operator) have started a new life in Granada, while Illona Söchting moved to Oxford to work onthe Gemini telescope project. Mischa Schirmer and Samantha Rix, both with extensive experience in observationalastronomy, have joined the team.
All those who have left ING and have worked hard to make ING into the successful observatory it is today are wished well intheir new carreers.
THE ING NEWSLETTER No. 8, September 2004
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T he ING organised a Short Course in Adaptive Optics in collaboration with Imperial College London, University ofDurham and the National University of Ireland. The course was held on the 12–14th January 2004 in Los Cancajos,
La Palma.
It was adapted for observatory staff and designed to explain the basic principles of adaptive optics, provide an introductionto wavefront sensing techniques, describe the components currently used for adaptive optics, identify new technologiesof potential importance for incorporation into adaptive optical systems, describe current applications of adaptive opticsand identify new applications.
The course was taught by Prof Chris Dainty, Dr Gordon Love, Dr Richard Myers and Dr Carl Paterson and contained atrip to the WHT to look at its adaptive optics instrumentation. Local organiser was Stephen Goodsell (ING). ¤
A Short Course in Adaptive Optics Organised by ING
Course room at Hotel H10 TaburientePlaya, Los Cancajos.
Visits to ING and Open DaysOn 18 July and 15 August two Open Days were organised, on which the publicwas invited to visit both the WHT and the INT. The total number of visitorswas 2853 split into 80 tours. Also on 20 August another Garafía’s Day wasorganised on which 160 people in 4 tours were shown round the WHT. Apartfrom Open Days, a total of 1862 visitors in 84 tours were shown round theWHT and occasionally the INT from December 2003 to August 2004.
Some VIP visitors in the last 10 months were: the Presidente of AURA, BillSmith, and the NSO director (ATST-IP), Steve Keil, visited the WHT on 27October; on 29 January the Spanish astronaut Pedro Duque visited the WHT(see photo top right); on 25 July the Spanish Education and ScienceMinister, María Sansegundo, visited the WHT at night accompanied byother ministry members (see photo bottom right); on 26 August the presidentof the Spanish Research Council, Carlos Martínez, visited the WHT. ¤
Course lecturers. From left to right: ProfChris Dainty, Dr Gordon Love, Dr RichardMyers and Dr Carl Paterson.
Happy Birthday INT !
On 13 February 2004 the Isaac Newton Telescopewas 20 years of continued operation on La Palma.During this period of time the INT has producedan impressive contribution to astronomy research:more than 1100 papers published in refereedjournals. We thank all the staff and visitingastronomers who have made this possible ! Theaccompanying pictures show the INT in its formerlocation in Hertsmonceux in the late 60s, theofficial inauguration on La Palma on the 29th ofJune, 1985 and a recent picture of the telescope.
M83 Galaxy. Color images of this galaxy reveal a wide range of colors from the yellow central core of old stars to the blue spiral armsof young stars. Several red knots can also be seen These are gaseous nebulae where active star formation is taking place. Dark lanes ofdust are also visible throughout the galaxy’s disk. The image shown on the next page was obtained in February 2004 using the PrimeFocus Camera on the William Herschel Telescope, and it is a combination of filters Johnson B, V and R. Credit: Chris Benn (ING) andNik Szymanek (University of Hertfordshire).
M81 Galaxy. The image is a combination of exposures obtained in 2003 from Wide Field Camera on the Isaac Newton Telescope(courtesy of Jonathan Irwin) and Digitized Sky Survey 2 images. Credit: ESA/INT/DSS2.
M74 Galaxy. Its arms are traced with clusters of blue young stars and pinkish colored diffuse gaseous nebulae (HII regions), and reachout to cover a region of roughly 95,000 light years, or about the same size as our Milky Way galaxy. The image was obtained in August2004 using the Wide Field Camera on the Isaac Newton Telescope. The colour composite was built from filters B, V and R and usingAdobe Photoshop with the help of the ESA/ESO/NASA Photoshop FITS Liberator plugin. Credit: Simon Dye (Cardiff University).
No. 8, September 2004 THE ING NEWSLETTER
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New Additions to the ING Collection of Messier Objects
E l Niño happens when tropical Pacific Ocean trade winds die out and ocean temperatures become unusually warm. There is a flipside to El Niño called La Niña, which occurs when the trade winds blow unusually hard and the sea temperature become colder
than normal. El Niño and La Niña are the warm and cold phases of an oscillation referred to as El Niño/Southern Oscillation, or ENSO.Although ENSO originates in the tropical Pacific ocean-atmosphere system, it has effects on patterns of weather variability all over theworld. It is believed, for instance, that El Niño conditions suppress the development of tropical storms and hurricanes in the Atlantic,and that La Niña favors hurricane formation.
The index used to monitor the coupled oceanic-atmospheric character of ENSO is called the Multivariate ENSO Index (MEI) based on themain observed variables over the tropical Pacific. The MEI can be understood as a weighted average of the main ENSO features containedin the following six variables: sea-level pressure, the east-west and north-south components of the surface wind, sea surface temperature,surface air temperature, and total amount of cloudiness. Positive values of the MEI represent the warm ENSO phase (El Niño).
On the William Herschel Telescope weather observing downtime is recorded by observers when the following happens: humidity ishigher than 90%, mirror temperature is less than 2 degrees of the dew point, wind speed is higher than 80km/h (or gusts for more than10 seconds are above 80 km/h), dust is clearly visible in the beam of a torch, or if the dome shows any resistance to movement due tothe presence of ice.
In spite of the inaccuracies present in the process of recording weather downtime, and the fact that several elements contribute to thedowntime apart from rain, it is possible to see some teleconnection between the MEI index and the percentage of weather downtime asit is shown in the accompanying plots. A study of rainfall and MEI carried out at Teide Observatory on Tenerife (Sergio SuárezIzquierdo, 2003, “Relaciones observadas entre el fenómeno de “El Niño” y las precipitaciones en la isla de Tenerife”, I Encuentro sobreMeteorología y Atmósfera de Canarias, DG-INM, November 2003, p. 51.) came to a similar conclusion. ¤
Detection of “El Niño” Effect at the Roque de los MuchachosObservatory?Javier Méndez (ING) and Sergio Suárez (Asociación Canaria de Meteorología)
Left: Comparison between the percentage of weather observing downtime at the William Herschel Telescope and the Multivariate ENSO Index (MEI)averaged from June to December inclusive (when the highest correlation is found). Only the episodes with averaged MEI positive in the period June-May are considered, ie. when the El Niño effect took place in the interannual period June-May then we averaged weather downtime and MEI indexfor the corresponding period June-December. Right: Same data as before. Correlation of linear regresion is r = –68 or confidence level of 95%.
M83 Galaxy
M74 Galaxy
M81 Galaxy
No. 8, September 2004 THE ING NEWSLETTER
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TELESCOPE TIME
The long-slit intermediate resolutioninfrared spectrograph, LIRIS, is offered inboth imaging and long-slit spectroscopymodes. LIRIS in multi-slit mode is availableonly in collaboration with the instrumentbuilders due to the very long lead timerequired with the mask creation andinsertion into the cryostat. Prospectiveapplicants for LIRIS in this mode shouldcontact Arturo Manchado ([email protected])in the first instance. In the current yearfurther commissioning will take placeduring which the multislit mask operationsare further fine-tuned. In addition, severaltechnical improvements have to be verifiedon sky (e.g. new sandwich holders for thelong slits), and a thorough quantificationof the image quality will be performed.Presently it is only possible to use the lowresolution grism (ℜ ∼1000), the higherresolution spectroscopic mode (ℜ ∼3000) andthe polarimetric modes of this instrumentare delayed pending purchase of therelevant grisms and prisms. Since theperformance of LIRIS in imaging mode isvery similar to that of INGRID, we do notplan to offer the latter at the Cassegrainfocal station while LIRIS is operational.
Override observations of targets ofopportunity are an increasingly importantaspect of telescope operations. At any giventime we have a number of active overrideprogrammes and, due to the nature of thetime-split at ING between four separateTACs, the rules and restrictions applying
to these programmes are rather complicated.Those interested in applying for suchprogrammes should therefore familiarisethemselves with the information on our webpages at http://www.ing.iac.es/Astronomy/observing/overrides.html. It may well bethe case that a cross-TAC approach wouldmake most efficient use of telescope timeand maximise chances of a successfuloverride campaign.
The WHT and INT are now part of the EUfunded access programme managed underthe auspices of Opticon. Applicants awardedtime on these telescopes under the normalpeer review processes, but who are noteligible for financial support from thetelescopes’ funding agencies, may apply tosupport under this access programme.The programme is funded to run fromJanuary 2004 until December 2008, andfull details of the scheme can be found athttp://www.otri.iac.es/eno/. ¤
I n newsletter issue No. 6 (October2002) we reported on the constructionof the new ‘long camera’ for WYFFOS,
the multi-object spectrograph used inconjunction with AF2 and INTEGRAL. Itis a pleasure to report that this camerawas successfully commissioned, in fact atthe time of writing the final commissioningrun is underway. First indications are thatthe camera is performing to specification,full details will appear on the AF2 webpages in due course. We currently use thetwo-chip EEV array with the long camera,which while it has excellent blue response,suffers from significant fringing in the red.We are actively pursuing the purchase ofCCDs with good overall efficiency andfringing characteristics. When the array isused with AF2 the dispersion direction isaligned with the array such that one loosesone central fibre and care should be takento park this fibre when field configurationsare performed. The new camera permitsthe placement of 150 fibres on the CCDarray, and typically gives 4-pixel samplingper resolution element, equivalent toresolving powers of approximately 5000and 1500 with the 1200R and 600B gratingsrespectively (depending on wavelength).When the long camera is used withINTEGRAL it is rotated by 90 degreesleading to gaps in wavelength space whichneed to be taken into account when defininga central wavelength.
Telescope Time Awards Semester 2004A
Service proposals not included. For observing schedules please visitthis web page: http://www.ing.iac.es/ds/sched/. University orinstitution of principal investigator between parentheses.
William Herschel Telescope
UK PATT
– Charles (Southampton). Determining system parameters of a SoftX-ray transient in outburst. W/2004A/36
– Charles (Southampton). The Mass Donor in SS43. W/2004A/56– Harries (Exeter). Spectropolarimetry of symbiotic binaries. W/2004A/6– Haswell (OU). Accretion Disc Precession in AM CVn. W/2004A/49– Hodgkin (IoA). Spectroscopic Identification of Very Low-Mass Stars
and Brown Dwarfs in Young Open Clusters. W/2004A/54
– Jarvis (Oxford). Quantifying the space density of radio-loud quasarsat z > 5. W/2004A/19
– Jeffery (Armagh). PG1544+488 and other helium-rich subdwarfs:binaries, mergers or bizarre. W/2004A/45
– Keenan (QUB). The space density of B-type stars in the Galactic halo.W/2004A/3
– Lucas (Hertfordshire). PLANETPOL polarimetry of Tau Boo Ab.W/2004A/27
– López (IAC). Morfología cuantitativa de las galaxias delsupercúmulo de Hércules. I1/2004A
– López (IAC). Tracing the Intracluster Light in Virgo Cluster.I2/2004A
– Mampaso (IAC). Planetary nebulae and the intergalactic stellarpopulation in the intragroup medium. I6/2004A
– Vázquez (IAC). Oscilaciones Estelares y Solares. I5/2004A
Spanish Additional Time
– Herrero (IAC). Detectando la población de estrellas masivas azuleshasta 5 Mpc para OSIRIS. I11/2004A
– Vílchez (IAA). An Hα search for star-forming galaxies in nearbyclusters. I14/2004A
Telescope Time Awards Semester 2004BService proposals not included. For observing schedules please visitthis web page: http://www.ing.iac.es/ds/sched/. University orinstitution of principal investigator between parentheses.
ITP Programmes on the ING Telescopes
– Gäensicke (Warwick). Towards a Global Understanding of CloseBinary Evolution. ITP7
William Herschel Telescope
UK PATT
– Bunker (Exeter). Star formation at redshift ~1. W/2004B/56– de Blok (Cardiff). Deep K-band surface photometry of low surface
brightness galaxies. W/2004B/30– Dhillon (Sheffield). ULTRACAM observations of the transiting
extrasolar planet HD209458b. W/2004B/14– Dufton (QUB). Spectroscopy of h + χ Persei to support VLT/FLAMES
survey of the Magellanic Clouds (payback). W/2003B/3– Gaensicke (Warwick). HS2331+3905: A cataclysmic variable in its
final days? W/2004B/37– Hirtzig (Meudon). Titan’s surface and atmosphere: in-depth diagnostic
via spectro-imagery. W/2004B/69– Jeffers (St Andrews). High-resolution Doppler Imaging of RS CVn
SV Cam. W/2004B/33– Jeffery (Armagh). Mode identification from multicolour photometry
of the pulsating sdB star PG 0014+067. W/2004B/44– Knigge (Southampton). Spectroscopic reconnaissance of candidate
emission line stars discovered by IPHAS. W/2004B/71– Kotak (ICL). Optical spectroscopic study of the physics of nearby
Type Ia Supernovae. W/2004B/16– Kotak (ICL). Optical spectroscopic study of the physics of nearby
Type Ia Supernovae. W/2004B/17– Leven (Leicester). GRBs as cosmological probes. W/2004B/60– Littlefair (Exeter). The quiescent accretion disc in the dwarf nova IP
Peg. W/2004B/31– Lucas (Hertfordshire). PLANETPOL polarimetry of Upsilon
Andromedae b. W/2004B/6– Marsh (Warwick). Stochastic Variability of Accreting White Dwarfs.
W/2004B/21– Marsh (Warwick). Magnetism in “non-magnetic” cataclysmic variable
stars. W/2004B/66– Maxted (Keele). Eclipsing binaries in open clusters — spectroscopy.
W/2004B/40– McLure (IoA). Exploring the connection between bulge/black-hole
mass and radio luminosity from z=0 to z =2. W/2004B/34
– Meikle (ICL). Late-time study of the nearby type IIP Supernova2004am. W/2004B/38
– Meikle (ICL). Direct detection and study of supernovae in nuclearstarbursts. W/2002B/56 LT
– Merrifield (Nottingham). Gravitational Redshift in M32 and theProperties of its Stellar Population. W/2004B/39
– Nelemans (IoA). Testing common envelope theory and SN Iaprogenitor models with double white dwarfs. W/2004B/47
– Royer (Leuven). A complete survey of the Wolf-Rayet content of M33.W/2004B/28
– Smith (Hertfordshire). The High and Low Ionization Broad-LineRegion in Quasars. W/2004B/5
– Tanvir (Hertfordshire). The physics of short bursts and relativisticblast waves. W/2004B/51
– Vink (ICL). A search for evidence of accretion in Herbig Be stars.W/2004B/4
– Wilkinson (IoA). Dark matter in the Sextans dwarf spheroidal.W/2004B/70
NL NFRA PC
– Aerts (Nijmegen). Asteroseismology of the pulsating sdB star PG0014+067. w04bn015
– de Zeeuw (Leiden). Mapping the nuclear regions of SAURON early-type galaxies with OASIS. w04bn006
– Franx (Leiden). Infrared Spectroscopy of restframe Optically RedGalaxies at high redshift. w04bn008
– Groot (Nijmegen). Spectroscopic reconaissance of emission line starsdiscovered by IPHAS. w04bn013
– Groot (Nijmegen). The UV-excess and White Dwarf binary populationin the Faint Sky Variability Survey. w04bn014
– Groot (Nijmegen). The missing link of Cataclysmic Variable evolutionin the Sloan Digital Sky Survey? w04bn016
– McDermid (Leiden). Black hole masses from gaseous and stellarkinematics using OASIS+NAOMI. w04bn007
– Nelemans (Nijmegen). Testing common envelope theory and SN Iaprogenitor models with double white dwarfs. w04bn004
– Nelemans (Nijmegen). The masses of millisecond pulsars. I.Identification of suitable white dwarf companions. w04bn005
– Quirrenbach (Leiden). Line Bisector Variations for K Giant Starswith Possible Planetary Companions. w04bn011
– Trager (Groningen). The Stellar Populations of Gas-Selected Early-type Galaxies. w04bn003
– Wijers (Amsterdam). GRBs as cosmological probes. w04bn009– Wijers (Amsterdam). The physics of short bursts and relativistic
blast waves. w04bn012
THE ING NEWSLETTER No. 8, September 2004
3 1
SP CAT
– Arribas (STScI/IAC). The potential of Integral Field Spectroscopydetecting extrasolar planetary features: INTEGRAL observations ofHD209458b. W28/2004B
– Cairós (IAC). Multiwavelength studies of metal-poor Blue CompactDwarf Galaxies: unveiling their evolutionary state. W33/2004B
– Casares (IAC). Determining system parameters of a Soft X-raytransient in outburst. W2/2004B
– Castro-Tirado (IAA-CSIC). La naturaleza de las explosionescósmicas de rayos gamma (GRBs). W36/2004B
– Colina (IEM/CSIC). Estudio INTEGRAL de Galaxias InfrarrojasMuy Luminosas. W4/2004B
– Exter (IAC). Searching for chemical inhomogeneities in planetarynebulae (PNe). W18/2004B
– Gallego (UCM). The evolution of the Star Formation Rate density ofthe Universe up to z=0.8. W45/2004B
– González (IAC). Probing the Evidence of Supernova Event in theBlack Hole Binary A0620-00. W12/2004B
– Hatzidimitriou (Creta). Identificación de contrapartidas ópticas defuentes de rayos X en M33. W5/2004B
– Iglesias (Marseille). Formación estelar de galaxias en cúmuloscercanos. W21/2004B
– Magrini (Firenze). The chemical composition of HII regions in M33.W16/2004B
– Martínez (Valencia). La masa y la extensión de los halos en galaxiaselípticas. W10/2004B
– Martínez-Delgado (IAC). Does M31 have as many satellites aspredicted by Cold Dark Matter theory? W37/2004B
– Miranda (IAC). Procesos de fluorescencia en astrofísica: la excitaciónde OI 8446. W20/2004B
– Miranda (IAC). Procesos de fluorescencia en astrofísica: la excitaciónde OI 8446. WW20/2004B
– Santander (IAC). La estructura dinámica y evolución del remanentede la Nova Persei 1901. W6/2004B
– Shahbaz (IAC). Infrared spectroscopy of black hole X-ray transients:accurate mass determinations. W34/2004B
– Vazdekis (IAC). Using late-type spirals as a probe of galaxy formation.W39/2004B
– Zurita (Granada). Spectroscopic identification of Hα emittersdiscovered by IPHAS. W30/2004B
Spanish Additional Time
– Balcells (IAC). El muestreo GOYA. Caracterización fotométrica degalaxias a alto z. W46/2004B
– Cepa (IAC/ULL). El Proyecto OTELO: Cartografiado profundo en(B,V,R,I) en los campos SA68 y VIRMOS-0226. W22/2004B
– Corral (IAC/GTC). Estrellas Azules Luminosas en M33. W51/2004B– Herrero (IAC). Detectando la población de estrellas masivas azules
hasta 5Mpc para OSIRIS. W50/2004B– Manchado (IAC). LIRIS GT
TNG-TAC
– Boschin (Trieste). Radio-halo clusters and cluster mergers: ahomogeneous dynamical analysis of a large Northern sample. T29
– Fasano (OAP). Star formation and morphological evolution of galaxiesin nearby clusters with WYFFOS. T12
– Galleti (Bologna). The Globular Cluster system of M31: a radialvelocity survey for 86 candidates and the M31 total mass. T37
Instrument Builder’s Guaranteed Time
– Bacon (Lyon). OASIS. GT Type A– Bacon (Lyon). OASIS. GT Type B
Isaac Newton Telescope
UK PATT
– Aigrain (IoA). Searching for planetary transits in the Orion NebulaCluster. I/2004B/19
– Dowsett (IoA). A systematic study of AGN within distant galaxyclusters. I/2004B/18
– Drew (ICL). IPHAS: the INT/WFC photometric Hα survey of thenorthern galactic plane. I/2004B/10
– Jarvis (Oxford). A wide-field search for Lyman-α haloes: A pre-requisite for massive galaxy formation? I/2004A/17 LT
– Littlefair (Exeter). How long do young stars remain locked to theirdiscs? I/2004B/14
– McMahon (IoA). Photometric Calibration of the XMM-NewtonSerendipitous Survey Imaging Program. I/2004B/23
– Murphy (IoA). Testing CDM with galaxy rotation curves at largeimpact parameters. I/2004B/4
– Rawlings (Oxford). Tracing star-formation in two formingsuperstructures. I/2004B/7
– Vlahakis (Cardiff). The Optically-Selected SLUGS: A systematicsurvey of the Local Submillimetre Universe. I/2004B/13
NL NFRA PC
– Aragon (Groningen). Measuring Galaxy Spin Alignments along thePisces-Perseus Ridge in the Vicinity of A262. i04bn001
– Braun (NFRA). The STARFORM/Hα survey: Probing the recenthistory of star formation in spirals. i04bn004
– Groot (Nijmegen). IPHAS: the INT/WFC photometric Hα survey ofthe northern galactic plane. i04bn006
– Groot (Nijmegen). A HeI survey of the Galactic Plane: The AM CVnpopulation. i04bn007
– Helmi (Groningen). The role of minor mergers in the build up of theMilky Way halo. i04bn003
SP CAT
– Barrena (IAC). Caracterización fotométrica y morfológica de cúmulosde galaxias con emisión difusa en radio y rayos X. I7/2004B
– Beckman (IAC). The links between bars and star formation: Anadvanced survey. I10/2004B
– Castro-Tirado (IAA-CSIC). La naturaleza de las explosiones cósmicasde rayos gamma (GRBs). W36/2004B [sic]
– Deeg (IAC). Sample Definition for Exoplanet detection by the COROTSpace Craft. I9/2004B
– López (IAC). Luz Difusa en Grupos Compactos de Galaxias. I5/2004B– Negueruela (Alicante). Contrapartidas ópticas a fuentes Newton-
XMM en cúmulos abiertos. I3/2004B– Rosenberg (IAC). Formación y Evolución de la Vía Láctea (III): El
Disco Galáctico. I8/2004B
Spanish Additional Time
– Barrado (LAEFF-INTA). Exploring the different IMFs in the LambdaOri SFR. I1/2004B
– Herrero (IAC). Detectando la población de estrellas masivas azuleshasta 5 Mpc para OSIRIS: Completando La población de M33.I11/2004B
– Vílchez (IAA). A Deep Search for Star-Forming Galaxies in NearbyClusters. I4/2004B
Abbreviations:
CAT Comité para la Asignación de TiempoITP International Time ProgrammeLT Long termNFRA 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 Kingdom
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 Manager Kevin Dee 405565 kmdTelescope Scheduling Ian Skillen 425439 wjiService Programme Pierre Leisy 425441 pleisyWHT Telescope Manager Chris Benn 425432 crbINT Telescope Manager Romano Corradi 425461 rcorradiInstrumentation Technical Contact Tom Gregory 425444 tgregoryFreight Juan Martínez 425414 juanHealth and Safety Juerg Rey 405632 juergPublic Relations Javier Méndez 425464 jma
