italian contribution to the eso instrumentation, from la...

Mem. S.A.It. Vol. 83, 1134c© SAIt 2012 Memorie della

Italian contribution to the ESO instrumentation,from La Silla to the E-ELT

S. D’Odorico

European Southern Observatory – K.Schwarzschild Str. 2, 85748 Garching by Munich,Germany, e-mail: [email protected]

Abstract. An overview is presented of the development of optical and infrared instrumen-tation at ESO from 1980 to 2012, a period which covers the build up of the La Silla andParanal observatories and the plans for the E-ELT. The contributions by Italian institutes tothe instrumentation projects at the different telescopes are described and the future prospectsoutlined.

Key words. Optical telescopes – Instrumentation

1. Introduction

In this paper the optical and infrared instru-mentation built and planned by the EuropeanSouthern Observatory (hereafter ESO) forthe telescopes in its Chile Observatories areoverviewed and the contributions by the Italianinstitutes presented. ESO was established asan European Institution in 1962 with the goalto build an optical astronomical observatoryin the southern hemisphere. In 1963 Chilewas selected as the country where to estab-lish the Observatory with a first site devel-oped starting in 1965 on the La Silla moun-tain ridge, in the Atacama desert, 85km north-east of the town of La Serena. A second ESOAtacama site, the Paranal peak, 110km southof Antofagasta, was chosen to host the VeryLarge Telescope (hereafter VLT). The ParanalObservatory started operation 1998 and in-cludes 4x8.m telescopes + 4 1.5m position-able telescopes for interferometry. Two widefield survey telescopes, one for the infrared

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(VISTA) and one for the visual (VST) wereadded in 2009 and 2011 respectively.

Italy joined the organization as a membercountry in 1982. The development of ESO in-strumentation for the La Silla larger telescopes,the 3.6m (1976), 2.2m (1982) and 3.5m NewTechnology Telescope (NTT, 1989) are sum-marized in section 2. The instrumentation builtfor the telescopes of Paranal Observatory arelisted in section 3. The contribution on instru-mentation by Italian institutes for the two ob-servatories are described in these two sections.Section 4 presents the instrumentation studiescarried out between 2006 and 2009 for the 42mEuropean ELT project, for which construc-tion on the Cerro Armazones close to Paranalshould start in 2013. Final considerations onthe Italian participation to the ESO instrumen-tation effort are presented in section 5. Detailedinformation on the technical properties of dif-ferent instruments are not given here but can beeasily retrieved from the ESO web pages.

D’Odorico: ESO instrumentation and the Italian contribution 1135

2. Instrumentation development forthe La Silla Observatory 1980-2000

2.1. Overview of the ESO La Sillainstruments

The largest La Silla telescope, the 3.6m, sawfirst light in 1976 after a decade long de-sign and construction time. Instrument plan-ning and design for the 3.6m at ESO wasstarted after the move to the CERN premisesin 1970. The smaller telescopes which becomeoperational before the 3.6m operated with in-struments provided by European institutes. Theoperation efficiency suffered from the initiallack on the mountain of technical staff withknowledge and expertise in the instrumenta-tion. The first ESO-built instrument for the3.6m was the automatic camera at the prime-focus triplet corrector(1979)which operatedstill with photographic plates. With the moveof ESO Headquarters to Garching in 1980, adetector group working on CCDs and infrareddetectors was founded. As the photographicplates were being replaced by more efficientdetectors, the procurement and installation ofdigital detector was a key step for a success-ful instrumentation program. The first spec-troscopic device at the 3.6m was a commer-cial Boller & Chivens spectrograph equippedwith a 1D Image Dissector Scanner and ,fora few visiting runs in the first years of oper-ation of the telescope, with the Image PhotonCounting System of the University College.The Echelle Cassegrain spectrograph with aCCD detector (CASPEC) was the first ESO-built spectrograph installed at the 3.6m. It wasfollowed by another innovative ESO instru-ment, the Faint Object Spectrograph Camera(EFOSC) which combined the spectroscopicand imaging modes and the efficiency of thenew CCD detectors to study the faintest galac-tic and extragalactic sources. The EFOSC con-cept was copied by several similar instrumentsat medium-large telescopes world-wide andwas essentially duplicated for the 8-10m classtelescopes.

It was also through the success of thesehome-made instruments in the first part of the1980 decade that ESO gathered the consensusin the community to have the VLT project ap-

proved in 1987, before the new large telescopeon La Silla, the NTT, saw first light in 1989.Table 1 summarizes the main instruments op-erating since 1980 at the three larger La Sillatelescopes. The last two columns give the num-ber of refereed papers using data from a giveninstrument (as derived from the data base of theESO library) and the years of operations. Thegood quality of the instrumentation and of themaintenance and operation at the observatorycan be appreciated by the very long lifetime ofmost instruments and by the large number ofrefereed papers.

While the larger fraction of the instru-ments for the La Silla Observatory was de-signed and built by ESO, a few projects werebuilt by institutes in collaboration with ESO.The external technical and financial contribu-tions were compensated with observing nightsat the telescopes where the instruments wereinstalled (the so-called guaranteed observingtime- or in short GTO). In this category fallsthe two Adaptive Optics prototype instrumentsCOME ON + and ADONIS and the multi armfield spectrograph MEFOS, all at the 3.6m,the FEROS echelle, fiber-fed spectrograph atthe 1.5m (later moved to the 2.2m) and theWide Field Camera at the 2.2m. This expe-rience was useful to test at the telescope tech-niques like AO which were just being devel-oped and to acquire instrumentation on a fasttrack when limited by ESO manpower or theavailable budget. The approach was followedmore systematically for the VLT instrumen-tation program from 1990 on (see section 3).In the VLT era two other instruments built incollaboration with consortia of external insti-tutes were installed at the 3.6m: TIMMI2 andHARPS. These collaborations opened to theESO community a new spectral range, the midinfrared with TIMMI2 and a new observingtechnique, the highly accurate radial velocityspectroscopy, with HARPS.

2.2. The Italian contributions

Italy joined ESO as member state in May1982. Its main contribution to the La SillaObservatory were the innovative mechanicalstructure and dome of the New Technology

1136 D’Odorico: ESO instrumentation and the Italian contribution

Telescope which were built by Italian firmswith the funds provided by the membershipfees paid by Italy and Switzerland. As of col-laborations on instrumentation, starting in the80s, the Observatory of Trieste collaboratedextensively (1985-1995, see the contributionby P. Santin in this volume) with ESO on thesoftware for remote control of instruments andtelescopes from Garching. The remote controlbecome for several years an offered observingmode for the Coude Echelle Spectrograph atthe CAT telescope and for instruments at the2.2m and at the NTT. An experiment of remotecontrol of EMMI at the NTT was successfullyrealized from the Trieste Observatory, via alink through the ESO Headquarter in Germany.

The Roma Observatory collaborated withESO on the construction of SUSI2, an im-proved version of the NTT direct camera tobe used in superb seeing conditions.It wasbuild in a record time of two years, 1995-1997

(D’Odorico 1995). The contribution by theRoma Observatory was 320 kDM and 2 FTE,in exchange of 25 GTO nights. The camera wasused by ESO and Roma astronomers to obtainthe first ground-based, multicolor, high imagequality deep field 1. Figure 1 shows the com-bined deep image.

An additional contribution to the LaSilla instrumentation was provided by theOsservatorio di Capodimonte for the construc-tion of the CCD mosaic Wide Field Imager atthe 2.2m. A cash contribution of 500kDM and1 FTE was provided in exchange of 30 GTOnights.

1 www.eso.org/sci/activities/garching/projects/ndf.html

www.eso.org/sci/activities/garching/projects/ndf.html

www.eso.org/sci/activities/garching/projects/ndf.html


Fig. 1. BVri combined image of the NTT SUSI2deep field , one of the first attempt of this type ofdeep imaging from the ground, chosen as NASAPicture of the day on September 15,1998. The im-age quality of the combined images is below 1 arcsec in all bands, the total exposure times vary from54ksec (B) to 15ksec(i), see (Arnouts et al 2000),(Fontana et al. 2000).The camera project and thesurvey were the result of a collaboration betweenESO and the Observatory of Roma

3. Instrumentation development forthe Paranal Observatory

3.1. The 1st Generation VLT instruments

Long before the VLT first light, in 1989, ESOreleased an instrumentation plan where the firstgeneration of instruments was outlined and thepolicy of instrument procurement in collabo-ration with the external institutes spelled out.11 instruments were foreseen for the 12 focuspositions at the 4 8m telescope (8 Nasmyth +4 Cassegrain), with one position left free forvisiting instruments. The largest fraction of in-struments had to be built by consortia of in-stitutes in the member states with the projectsbased on a set of agreed specifications, fol-lowing strict standards in electronic compo-nents and in the control and acquisition soft-ware and subjected to a regular review pro-cess. ESO does contribute to the externally-ledprojects with cash for the hardware procure-ment and with selected subsystems. ESO does

also take care of the procurement and testingof both state-of-the-art CCD devices and IR ar-ray and supplied the fully integrated and oper-ational detector systems to all of the VLT in-struments.

The plan contained an outline of the firstinstrument complement and was later updatedbased on the progress of the observing tech-niques and components and the changes in sci-ence priorities. At the completion of the firstgeneration of instruments, of the 11 instru-ments 4 were built by ESO and 7 by Consortialed by external P.I.. The external contribu-tions in cash and FTE were compensated byESO with VLT GTO nights, at a rate of 1night/50kEUR. This instrument procurementapproach made possible the timely realiza-tion of the ambitious instrumentation programwithin budget. It favored the active participa-tion of a large fraction of the scientific com-munity to the project and permitted an earlyimplementation at the VLT of advanced tech-niques like adaptive optics, the use of laserguide stars and image slicing for integral fieldspectroscopy. For the institutes the advantagewas , and still is for the running and futureprojects, the possibility to build up a compe-tent technical team around the project, with thesupport of the national agencies for the infras-tructure costs. To the scientists in the consor-tium the GTO nights offer the great opportu-nity to carry out deep investigations which canhave a major impact in their field of research.

Table 2 lists the current complement of in-struments at the four 8m telescopes. They cor-responds to the 1st generation of VLT instru-ments with the exception of the X-shooter, thefirst instrument of the second generation whichreplaced FORS1 in 2009. The table reports thecurrent lifetime at the telescope of each instru-ment and the number of refereed papers usingdata from a given instrument (as derived fromthe data base of the ESO library). These num-bers show that the first instruments exceededthe originally specified 10 years of operationsand that the scientific production as measuredby the number of published papers is very high.

An additional instrument used at the VLTis MAD, the Multi-conjugate Adaptive OpticsDemonstrator. It is not listed in Table 2 because


it was installed at the visitor focus for a fewdedicated runs only during 2005 and 2006. Itdelivered for the first time on a large telescopesuccessful observations of several astronomi-cal targets with layer-oriented adaptive optics.

After completion of the four 8m , ESO didput in operation a coherent light combined fo-cus for interferometry which can be fed by fourauxiliary telescopes of 1.5m and the four 8m.The instrumentation for this focus was entirelyprovided by external consortia.

3.2. The Italian contribution to 1stGeneration VLT instruments

The Observatory of Trieste provided forUVES, an instrument built by ESO and thethird to be installed, important segments ofthe instrument control software, the secondaryguiding software and the observing templates(Santin 2012). It was a technical collaborationand no GTO was involved.

VIMOS was build by a French-Italianconsortium with an Italian coPI. INAF OACapodimonte and IAFC Milano were respon-sible for the opto-mechanics, electronics, ob-serving software, data reduction software andthe mask manufacturing unit. The Consortiumwas compensated with 70 GTO nights, whichwere used in a coordinated way by the team.

FLAMES was an instrument built underESO responsibility and in collaboration withFrench, Italian and Swiss institutes. The Italiancontributions came from INAF OA Trieste andBologna and covered the instrument controlsoftware and the observing templates. INAFreceived 11 GTO nights.

The INAF Observatories of Padova andArcetri contributed to the MAD prototype withthe wavefront sensors and the ICS, at a cost toINAF of 70kEUR and 3 FTE in exchange of 6GTO nights.

Two important contributions were also pro-vided on interferometry. In the same time


frame than the VLT instruments, INAF OATorino did build in collaboration with ESOFINITO (2004), a three beams fringe trackeroperating in the H band. The INAF contribu-tion was 300 kEUR and 8 FTE and was com-pensated with time at the small interferometrytelescopes and 8 VLTI nights. The second in-terferometry project with Italian participationwas AMBER (2008), a NIR spectrograph to beused with up to 3 beams. It was developed bya French, German, Italian consortium. INAFOA Arcetri did design and build the cryogenicspectrometer. The Italian share was 335 kEURand 10 FTEs, or about 20%.

It is worth noting here that many INAFinstitutes (the observatories of Arcetri, Brera,Capodimonte, Catania, Padova, Roma andTrieste) at the time of the constructionof the first generation of VLT instrumentswere strongly involved in the completion ofthe Galileo telescope and its instrumentation(DOLORES, SARG, NICS) and in the LargeBinocular Telescope for which they providedthe Prime Focus Cameras and the AO system.

3.3. The 2nd Generation VLTinstruments

With a call for proposals issued in 2001, ESOlaunched a first batch of 2nd generation VLTinstruments. Table 3 lists the currently ap-proved projects. X-shooter, the first of the 2ndgeneration, was already included in Table 2 asan instrument in operation and it is not du-plicated here. There are to this date four in-struments approved for the 8m UT foci, one,ESPRESSO, for the incoherent light combinedfocus and two for the interferometry focus. Thenew instruments are not up-to-date versions ofthe instruments currently in operation but en-able new observing techniques which will beused for the first time at the VLT.

3.4. The Italian contribution to 2ndGeneration VLT instruments

The Italian participation is very significant onthree of the new instruments. X-shooter is athree arms, intermediate resolution spectro-graph designed to provide instantaneous cov-

erage over the full spectral range from the UVto the K band. Among the five partners in theX-shooter project (Denmark, Italy, Holland,France and ESO) Italy contributed with 800kEUR and 19 FTE, or about 25 % of the totaleffort. The institutes involved were the INAFObservatories of Brera, Trieste, Palermo andCatania. They provided the UV and VIS spec-trographs and the instrument control software.The project was steered by a board of five coPI,one of them Italian. INAF received 45 GTOnights to compensate for the cash and FTE ef-fort.

SPHERE, a planet detection instrument us-ing extreme AO with three observing modes -imaging, IFS and polarimetry- is a six partnersproject (France, Germany, Italy, Switzerland,The Netherlands and ESO). The ProjectScientist is Italian. The INAF Observatoriesof Padova, Catania, Capodimonte and IASFMilano are contributing with the IFS unit,theinstrument control software and the scientificprogram. INAF’s share of the effort is 500kEUR and 28 FTEs, or about 20 % of the total.The consortium will receive 250 GTO nightswhich will be used mainly for a coordinatedsurvey of the most promising planetary sys-tems.

ESPRESSO, the counterpart of the 3.6minstrument HARPS at the VLT, will be thefirst instrument at the focus where the inco-herent light beams of the four 8m telescopesare combined, close to the interferometry fo-cus. It is being built by a consortium of insti-tutes in four countries (Italy, Portugal, Spainand Switzerland) and ESO. Italy is representedby one coPI and provides the Project Scientist.The INAF Observatories of Brera and Triestewill be responsible for the delivery of the spec-trograph front end unit,the exposimeter, thecontrol electronics and software, the observa-tion and data analysis software. INAF contri-bution amounts to 500 kEUR and 20 FTE,which represents about 25% of the total effort.

3.5. The Paranal Survey Telescopes

Two additional survey telescopes, the 2.5mVISTA -dedicated to a large field NIRobservations- and the 2.2m VST- dedicated


to wide field optical imaging- were added toParanal operation in 2009 and 2011 respec-tively. The VST project was initiated by theObservatory of Capodimonte which carried outmost of the telescope design and procurementand covered the cost. In the final phase INAFtook care of the completion and the commis-sioning on Paranal. The Italian contribution isbeing compensated with about 15 % of the ob-serving time with the telescope over the first 10years. The Observatory of Capodimonte partic-ipated also to the Consortium which in collab-oration with ESO did build the wide field CCDcamera OmegaCam for the telescope.

4. The OWL and E-ELT instrumentstudies

Starting in 2004, in parallel with the studyof the 100m OWL telescope, ESO launched8 studies for instruments to be coupled withthe new telescope. These were carried mainlyby external institutes and explored for thefirst time the parameter space of the observa-tions with a telescope of this size. Italian in-stitutes were active in this phase, with INAFOA Trieste involved in CODEX, an ultrastable,high resolution spectrograph, the Department

of Astronomy of the University of Padova inQuantEye, a high time resolution photometer,and the INAF Arcetri in ONIRICA, an infraredcamera with high angular resolution. When theOWL telescope was scaled to 42m and becomethe European ELT in 2007, a new batch of in-strument Phase A studies was carried out, toexplore the full range of observing capabili-ties on a wide selection of scientific programs.These are listed in Table 4, together with thetwo post-focal adaptive optics modules whichwere studied in parallel. Numerous Italian in-stitutes participated to the studies. They areidentified in table 4.

5. Overview and future prospects

As described in the previous sections, the par-ticipation of external institutes to the construc-tion of VLT and in the future to the E-ELT in-struments has gained an increasing relevancesince 1990. It has led to the establishmentof strong instrumentation groups in differentmember states and to the development of suc-cessful scientific programs through the use ofGTO. Italy joined ESO when most of the ESOeffort on instrumentation for the telescope atthe La Silla Observatory had been completed.


The participation in the first calls for VLTinstruments, a process which was started atthe end of the 80s, was still limited. Unlikeother ESO member states (France, Germany)Italy had not developed a 4m class nationaltelescope- the Galileo telescope started oper-ation in 1998- and observatories and labora-tories in Italy had therefore not acquired aspecific expertise on instrumentation for largetelescopes. It is with the second generation ofVLT instruments only that Italy could take ashare of the effort proportional to the strengthof its scientific and engineering community.Three out of the 8 currently approved 2nd gen-

eration VLT instruments ( X-shooter, Sphereand ESPRESSO) see a strong Italian partner-ship. The completion by INAF of the VST andthe successful start of operation, even if de-layed with respect to the original schedule, isnow a very positive result. The Italian partic-ipation is even more promising for the E-ELTinstruments and AO modules, where out of 11studies, 7 include a significant Italian partici-pation and 2 (SIMPLE, MAORY) are led byItalian P.I.. If the interest of the community willremain high and INAF will provide adequatesupport, this could lead to a strong Italian part-nership in the E-ELT instrumentation construc-


tion and consequently to a significant share inthe first exciting scientific programs carried outwith the new telescope.

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Zaggia, S., Fontana, A. 2000, A&A, 341,641Fontana, A., D’Odorico, S., Poli, F., Giallongo,

E., Arnouts, S., Cristiani, S., Moorwood, A.,Saracco, P., ApJ, 120,2206

D’Odorico, S. The Messenger, 91,15Santin, P. (2012), this volume

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