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The Very Large Telescope


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#1    Waspie_Dwarf

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Posted 25 February 2007 - 01:35 AM

The Sky Through Three Giant Eyes

The European Southern Observatory (ESO) press release 06-07 is reproduced below:

ESO 06/07 - Instrument Release

23 February 2007
For Immediate Release

The Sky Through Three Giant Eyes

AMBER Instrument on VLT Delivers a Wealth of Results


The ESO Very Large Telescope Interferometer, which allows astronomers to scrutinise objects with a precision equivalent to that of a 130-m telescope, is proving itself an unequalled success every day. One of the latest instruments installed, AMBER, has led to a flurry of scientific results, an anthology of which is being published this week as special features in the research journal Astronomy & Astrophysics.

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The AMBER instrument in the VLTI laboratory at Paranal.

"With its unique capabilities, the VLT Interferometer (VLTI) has created itself a niche in which it provide answers to many astronomical questions, from the shape of stars, to discs around stars, to the surroundings of the supermassive black holes in active galaxies," says Jorge Melnick (ESO), the VLT Project Scientist. The VLTI has led to 55 scientific papers already and is in fact producing more than half of the interferometric results worldwide.

"With the capability of AMBER to combine up to three of the 8.2-m VLT Unit Telescopes, we can really achieve what nobody else can do," added Fabien Malbet, from the LAOG (France) and the AMBER Project Scientist.

Eleven articles will appear this week in Astronomy & Astrophysics' special AMBER section. Three of them describe the unique instrument, while the other eight reveal completely new results about the early and late stages in the life of stars.

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The stellar wind regions of Eta Carinae. The artist's impression visualises the inner regions of Eta Carinae probed with AMBER at different wavelengths for
the first time. The figure shows the inner elongated stellar wind region observed in continuum light and the more extended region of the Brackett Gamma
line emission. The sizes of both zones are 4 and 10 milli-arcseconds (corresponding to 10 and 22 Astronomical Units). The dense stellar wind totally obscures
the central star.


The first results presented in this issue cover various fields of stellar and circumstellar physics. Two papers deal with very young solar-like stars, offering new information about the geometry of the surrounding discs and associated outflowing winds. Other articles are devoted to the study of hot active stars of particular interest: Alpha Arae, Kappa Canis Majoris, and CPD -57o2874. They provide new, precise information about their rotating gas envelopes.

An important new result concerns the enigmatic object Eta Carinae. Using AMBER with its high spatial and spectral resolution, it was possible to zoom into the very heart of this very massive star. In this innermost region, the observations are dominated by the extremely dense stellar wind that totally obscures the underlying central star. The AMBER observations show that this dense stellar wind is not spherically symmetric, but exhibits a clearly elongated structure. Overall, the AMBER observations confirm that the extremely high mass loss of Eta Carinae's massive central star is non-spherical and much stronger along the poles than in the equatorial plane. This is in agreement with theoretical models that predict such an enhanced polar mass-loss in the case of rapidly rotating stars.

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Radio map and VLTI measurements of the outburst of the binary system
RS Ophiuchi. The characteristics dimensions measured with AMBER on the
VLT Interferometer are shown as the blue, yellow and red lines -
corresponding to different wavelengths. They are overplotted on a radio
map of the same object obtained with the VLBA by O'Brien and colleagues.
The VLTI data were obtained 5.5 days after the outburst, while the radio
observations were done 13.8 days after the outburst. Clearly the material
released by the outburst has been expanding.


Several papers from this special feature focus on the later stages in a star's life. One looks at the binary system Gamma 2 Velorum, which contains the closest example of a star known as a Wolf-Rayet. A single AMBER observation allowed the astronomers to separate the spectra of the two components, offering new insights in the modeling of Wolf-Rayet stars, but made it also possible to measure the separation between the two stars. This led to a new determination of the distance of the system, showing that previous estimates were incorrect. The observations also revealed information on the region where the winds from the two stars collide.

The famous binary system RS Ophiuchi, an example of a recurrent nova, was observed just 5 days after it was discovered to be in outburst on 12 February 2006, an event that has been expected for 21 years. AMBER was able to detect the extension of the expanding nova emission. These observations show a complex geometry and kinematics, far from the simple interpretation of a spherical fireball in extension. AMBER has detected a high velocity jet probably perpendicular to the orbital plane of the binary system, and allowed a precise and careful study of the wind and the shockwave coming from the nova.

The stream of results from the VLTI and AMBER is no doubt going to increase in the coming years with the availability of new functionalities.

"In addition to the 8.2-m Unit Telescopes, the VLTI can also combine the light from up to 4 movable 1.8-m Auxiliary Telescopes. AMBER fed by three of these AT's will be offered to the user community as of April this year, and from October we will also make FINITO available," said Melnick. "This 'fringe-tracking' device allows us to stabilise changes in the atmospheric conditions and thus to substantially improve the efficiency of the observations. By effectively 'freezing' the interferometric fringes, FINITO allows astronomers to significantly increase the exposure times."

The Astronomy & Astrophysics special feature (volume 464 - March II 2007) on AMBER first results includes 11 articles. They are freely available on the A&A web site.

More Information

The AMBER consortium, led by Romain Petrov (Nice, France), includes researchers from the Laboratoire d'Astrophysique de Grenoble (France), Laboratoire d'Astrophysique Universitaire de Nice (France), Max-Planck Institut fŘr Radioastronomie (Bonn, Germany), INAF-Osservatorio Astrofisico di Arcetri (Italy), and the Observatoire de la C˘te d'Azur (Nice, France).

In March 2004, the first on-line tests of AMBER (Astronomical Multiple BEam Recombiner) were completed, when astronomers combined the two beams of light from the southern star Theta Centauri from two test 40-cm aperture telescopes (ESO 07/04). It was later used to combine light from two, then three Unit Telescopes of ESO's VLT and light from the Auxiliary Telescopes.

AMBER is part of the VLT Interferometer (VLTI) and completes the planned set of first-generation instruments for this facility. It continues the success story of the interferometric mode of the VLT, following the unique initial scientific results obtained by the VINCI and MIDI instruments, the installation of the four MACAO adaptive optics systems and the recent arrival of the last of the four 1.8-m Auxiliary Telescopes at Paranal.

The principle of the interferometric technique is to combine the light collected by two or more telescopes. The greater the distance between the telescopes, the more details one can detect. For the VLTI, this distance can be up to 200 metres, providing observers with milli-arcsecond spatial resolution. With such a high spatial resolution, one would be able to distinguish between the headlights of a car located on the Moon. In addition, AMBER also provides astronomers with spectroscopic measurements, allowing the structure and the physics of the source to be constrained by comparing the measures at different wavelengths.

AMBER combines the light beams from three telescopes - this is a world first for large telescopes such as the VLT. The ability to combine three beams, rather than just two as in a conventional interferometer, provides a substantial increase in the efficiency of observations, permitting astronomers to obtain three baselines simultaneously instead of one. The combination of these three baselines also permits the computation of the so-called closure phase, an important mathematical quantity that can be used in imaging applications.

The AMBER instrument is mounted on a 4.2 x 1.5-m precision optical table, placed in the VLT Interferometric Laboratory at the top of the Paranal mountain. The total shipping weight of the instrument and its extensive associated electronics was almost 4 tons.

Two of the results discussed here were already presented as ESO press releases in ESO 29/05 and 35/06.


Source: ESO Press Release pr-06-07

Edited by Waspie_Dwarf, 25 February 2007 - 02:03 AM.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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#2    SameerPrehistorica

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Posted 26 February 2007 - 11:26 AM

very interesting............nice pics
       thanks for the info.

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#3    Waspie_Dwarf

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Posted 28 March 2007 - 02:41 PM

Controlled by Distant Explosions

The European Southern Observatory (ESO) press release 17-07 is reproduced below:

ESO 17/07 - Science Release

28 March 2007
For Immediate Release

Controlled by Distant Explosions

VLT Automatically Takes Detailed Spectra of Gamma-Ray Burst Afterglows Only Minutes After Discovery


A time-series of high-resolution spectra in the optical and ultraviolet has twice been obtained just a few minutes after the detection of a gamma-ray bust explosion in a distant galaxy. The international team of astronomers responsible for these observations derived new conclusive evidence about the nature of the surroundings of these powerful explosions linked to the death of massive stars.

At 11:08 pm on 17 April 2006, an alarm rang in the Control Room of ESO's Very Large Telescope on Paranal, Chile. Fortunately, it did not announce any catastrophe on the mountain, nor with one of the world's largest telescopes. Instead, it signalled the doom of a massive star, 9.3 billion light-years away, whose final scream of agony - a powerful burst of gamma rays - had been recorded by the Swift satellite only two minutes earlier. The alarm was triggered by the activation of the VLT Rapid Response Mode, a novel system that allows for robotic observations without any human intervention, except for the alignment of the spectrograph slit.

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Screen shot of the message appearing on the Kueyen (UT2 of ESO's Very Large Telescope) console when the Rapid Response Mode is triggered by a distant explosion. The current observation is terminated and the telescope is preset to the site of the explosion to take spectra. Astronomers at the console can if requested stop the procedure. Otherwise, they just need to align the slit of the spectrograph before the observations can start. The whole procedure lasts a few minutes only.

Starting less than 10 minutes after the Swift detection, a series of spectra of increasing integration times (3, 5, 10, 20, 40 and 80 minutes) were taken with the Ultraviolet and Visual Echelle Spectrograph (UVES), mounted on Kueyen, the second Unit Telescope of the VLT.

"With the Rapid Response Mode, the VLT is directly controlled by a distant explosion," said ESO astronomer Paul Vreeswijk, who requested the observations and is lead-author of the paper reporting the results. "All I really had to do, once I was informed of the gamma-ray burst detection, was to phone the staff astronomers at the Paranal Observatory, Stefano Bagnulo and Stan Stefl, to check that everything was fine."

The first spectrum of this time series was the quickest ever taken of a gamma-ray burst afterglow, let alone with an instrument such as UVES, which is capable of splitting the afterglow light with uttermost precision. What is more, this amazing record was broken less than two months later by the same team. On 7 June 2006, the Rapid-Response Mode triggered UVES observations of the afterglow of an even more distant gamma-ray source a mere 7.5 minutes after its detection by the Swift satellite.

Gamma-ray bursts are the most intense explosions in the Universe. They are also very brief. They randomly occur in galaxies in the distant Universe and, after the energetic gamma-ray emission has ceased, they radiate an afterglow flux at longer wavelengths (i.e. lower energies). They are classified as long and short bursts according to their duration and burst energetics, but hybrid bursts have also been discovered (see ESO PR 49/06). The scientific community agrees that gamma-ray bursts are associated with the formation of black holes, but the exact nature of the bursts remains enigmatic.

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The 8.2-m Unit Telescope 2 of ESO's Very Large Telescope, Kueyen, is getting ready to observe.

Because a gamma-ray burst typically occurs at very large distances, its optical afterglow is faint. In addition, it fades very rapidly: in only a few hours the optical afterglow brightness can fade by as much as a factor of 500. This makes detailed spectral analysis possible only for a few hours after the gamma-ray detection, even with large telescopes. During the first minutes and hours after the explosion, there is also the important opportunity to observe time-dependent phenomena related to the influence of the explosion on its surroundings. The technical challenge therefore consists of obtaining high-resolution spectroscopy with 8-10 m class telescopes as quickly as possible.

"The afterglow spectra provide a wealth of information about the composition of the interstellar medium of the galaxy in which the star exploded. Some of us even hoped to characterize the gas in the vicinity of the explosion," said team member CÚdric Ledoux (ESO).

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All the telescopes on Paranal are operated from a central control room on the mountain. This photo shows the control desk of Kueyen (UT2) with a Telescope Operator and a Staff Astronomer.

The Rapid Response Mode UVES observations of 17 April 2006 allowed the astronomers to discover variable spectral features associated with a huge gas cloud in the host galaxy of the gamma-ray burst. The cloud was found to be neutral but excited by the radiation from the UV afterglow light.

From detailed modelling of these observations, the astronomers were able - for the first time - to not only pinpoint the physical mechanism responsible for the excitation of the atoms, but also determine the distance of the cloud to the GRB. This distance was found to be 5,500 light-years, which is much further out than was previously thought. Either this is a special case, or the common picture that the features seen in optical spectra originate very close to the explosion has to be revised. As a comparison, this distance of 5,500 light-years is more than one fifth of that between the Sun and the centre of our Galaxy.

"All the material in this region of space must have been ionised, that is, the atoms have been stripped of most if not all of their electrons," said co-author Alain Smette (ESO). "Were there any life in this region of the Universe, it would most probably have been eradicated."

"With the Rapid-Response Mode of the VLT, we are really looking at gamma-ray bursts as quickly as possible," said team member Andreas Jaunsen from the University of Oslo (Norway). "This is crucial if we are to unravel the mysteries of these gigantic explosions and their links with black holes!"

More Information

The two gamma-ray bursts were discovered with the NASA/ASI/PPARC Swift satellite, which is dedicated to the discovery of these powerful cosmic explosions.
Preliminary reports on these observations have been presented in GCN GRB Observation Reports 4974 and 5237. A paper is also in press in the journal Astronomy & Astrophysics ("Rapid-Response Mode VLT/UVES spectroscopy of GRB 060418 - Conclusive evidence for UV pumping from the time evolution of Fe II and Ni II excited- and metastable-level populations" by P. M. Vreeswijk et al.). DOI: 10.1051/0004-6361:20066780
The team is composed of Paul Vreeswijk, CÚdric Ledoux, Alain Smette, Andreas Kaufer and Palle M°ller (ESO), Sara Ellison (University of Victoria, Canada), Andreas Jaunsen (University of Oslo, Norway), Morten Andersen (AIP, Potsdam, Germany), Andrew Fruchter (STScI, Baltimore, USA), Johan Fynbo and Jens Hjorth (Dark Cosmology Centre, Copenhagen, Denmark), Patrick Petitjean (IAP, Paris, France), Sandra Savaglio (MPE, Garching, Germany), and Ralph Wijers (Astronomical Institute, University of Amsterdam, The Netherlands). Paul Vreeswijk was at the time of this study also associated with the Universidad de Chile, Santiago.


Source: ESO Press Release pr-17-07

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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#4    Waspie_Dwarf

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Posted 31 March 2007 - 04:09 AM

New Adaptive Optics Technique Demonstrated

The European Southern Observatory (ESO) press release 19-07 is reproduced below:

ESO 19/07 - Science Release

30 March 2007
For Immediate Release

New Adaptive Optics Technique Demonstrated

First ever Multi-Conjugate Adaptive Optics at the VLT Achieves First Light


On the evening of 25 March 2007, the Multi-Conjugate Adaptive Optics Demonstrator (MAD) achieved First Light at the Visitor Focus of Melipal, the third Unit Telescope of the Very Large Telescope (VLT). MAD allowed the scientists to obtain images corrected for the blurring effect of atmospheric turbulence over the full 2x2 arcminute field of view. This world premiere shows the promises of a crucial technology for Extremely Large Telescopes.

Telescopes on the ground suffer from the blurring effect induced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way which delights the poets but frustrates the astronomers, since it blurs the fine details of the images.

However, with Adaptive Optics (AO) techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e., approaching space conditions. Adaptive Optics systems work by means of a computer-controlled deformable mirror (DM) that counteracts the image distortion induced by atmospheric turbulence. It is based on real-time optical corrections computed from image data obtained by a 'wavefront sensor' (a special camera) at very high speed, many hundreds of times each second.

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The Multi-conjugated Adaptive optics Demonstrator (MAD) in operation at the Nasmyth A focus of Melipal, UT3 of ESO's Very Large Telescope.

The concept is not new. Already in 1989, the first Adaptive Optics system ever built for Astronomy (aptly named "COME-ON") was installed on the 3.6-m telescope at the ESO La Silla Observatory, as the early fruit of a highly successful continuing collaboration between ESO and French research institutes (ONERA and Observatoire de Paris). Ten years ago, ESO initiated an Adaptive Optics program to serve the needs for its frontline VLT project. Today, the Paranal Observatory is without any doubt one of the most advanced of its kind with respect to AO with no less than 7 systems currently installed (NACO, SINFONI, CRIRES and four AO systems for the interferometric mode of the VLT).

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Mosaic of images covering the central parts of Omega Centauri, the most luminous globular cluster as seen from Earth. The images were taken with CAMCAO in Br-gamma for a total exposure time of 5 minutes (the original pixel scale is 0.028 arcsec). The stars in the 2 arcmin field of view have a FWHM between 0.08 and 0.10 arcsec.

Present AO systems can only correct the effect of atmospheric turbulence in a relative small region of the sky - typically 15 arcseconds, the correction degrading very quickly when moving away from the central axis. Engineers have therefore developed new techniques to overcome this limitation, one of which is multi-conjugate adaptive optics (MCAO). At the end of 2003, ESO, together with partners in Italy and Portugal, started the development of a MCAO Demonstrator, named MAD.

"The aim of MAD is to prove the feasibility and performances of new adaptive optics techniques, such as MCAO, meant to work on large fields of view and to serve as a very powerful test tool in understanding some of the critical issues that will determine the development of future instruments, for both the VLT and the Extremely Large Telescopes," said Norbert Hubin, head of the AO group at ESO.

MAD is an advanced generation adaptive optics system, capable of compensating for the atmospheric turbulence disturbance on a large field of view (FoV) on the sky. It can successfully correct a 1-2 arcmin FoV, much larger than the ~15 arcsec typically provided by the existing adaptive optics facilities.

MAD was fully developed and extensively characterized by ESO using a dedicated turbulence generator (MAPS, Multi Atmospheric Phase screens and Stars) able to reproduce in the laboratory the temporal evolution and the vertical structure of the turbulence observed at the Observatory.

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In the Multi-Conjugate Adaptive Optics concept, several Guide Stars located in the Field of View are used simultaneously to perform a tomography of the atmospheric turbulence volume cone above the telescope by means of wavefront sensors. The measured wavefronts are combined in real-time to compute the commands applied to the deformable mirrors (two in the case of MAD) optically conjugated at different altitudes above the telescope. These deformable mirrors commands are optimized such as to homogeneously maximize the correction over the scientific field of view.

MAD was then disassembled and shipped to Paranal for re-integration at the Nasmyth Visitor focus of UT3. The integration took about 1 month, after which the system was ready for daylight testing and further characterization.

"On the night of 25 March, we could successfully close the first MCAO loop on the open cluster NGC 3293," said Enrico Marchetti, the MAD Project Manager. "The system behaviour was very stable and the acquisition and closed loop operations were fast and smooth."

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Maps of Strehl ratio (a measure of light concentration) in the case of single conjugated adaptive optics, i.e. as used in present AO systems (SCAO; left) and multi-conjugated (MCAO; right), as measured in images of Omega Centauri. Different colours correspond to different Strehl ratios, from 0 (black) to red (35%). The SCAO map illustrates how inhomogeneous the correction is across the field of view. The peak Strehl ratio is about 30% close to the guide star, to the right, and decreases with the distance to the guide star due to atmospheric anisoplanatism. The MCAO map, however, is much more uniform across the field of view, and peaks close to the location of the three guide stars shown by crosses. A comparison between the two images clearly shows the advantage of MCAO.

After routine checks on the closed loop stability and preliminary scans of the system parameters, the telescope was pointed to Omega Centauri, a very crowded area in the sky, and an optimal test case for extracting accurate measurements on AO correction performance with good spatial resolution on the FoV. Three 11 magnitude stars within a circle of ~1.5 arcmin diameter were selected as the baseline for wavefront sensing and the MCAO loop was closed successfully. Omega Centauri will be observed for several nights more, in order to test the AO correction in different seeing conditions.

"This is a tremendous achievement that opens new perspectives in the era of extremely large telescopes," said Catherine Cesarsky, ESO's Director General. "I am very proud of the ESO staff and wish to congratulate all involved for their prowess," she added.

The MAD images perfectly show the validity of the concept. The image quality was almost uniform over the whole field of view and beautifully corrected for some of the atmospheric turbulence.

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Central parts of the globular cluster Omega Centauri, as seen using different adaptive optics techniques. The upper image is a reproduction of PR Photo 19b/07, with the guide stars used for the MCAO correction identified with a cross. A box shows a 14 arcsec area that is then observed while applying different or no AO corrections, as shown in the bottom images. From left to right: No Adaptive Optics, Single Conjugate and Multi-Conjugate Adaptive Optics corrections. SCAO has almost no effect in sharpening the star images while the improvement provided by MCAO is remarkable.

More Information

The Multi-Conjugate Adaptive Optics (MCAO) Demonstrator MAD was built by ESO in collaboration with the Astronomical Observatories of Arcetri and Padova (Italy) and the Faculdade de Ciencias da Universidade de Lisboa (Portugal), as a pathfinder for 2nd generation VLT instrumentation and the European Extremely Large Telescope project.
The MCAO technique is based on probing the atmospheric turbulence on a large volume of atmosphere by means of several wavefront sensors (WFS), which point at different locations in the observed field of view, and by means of several deformable mirrors - optically conjugated at different altitudes on the atmosphere above the telescope - which correct for the atmospheric disturbance. The signals provided by the wavefront sensors are reconstructed to generate accurate information on the vertical structure of the atmospheric turbulence and then recombined in an optimal way to accomplish the best correction with the deformable mirrors located in the AO system. Since the wavefront sensors look at different directions in the field of view, the resulting correction is then optimized and homogeneously maximized across it. MAD makes use of two deformable mirrors, optically conjugated at 0 and 8.5 kilometres above the telescope.


Source: ESO Press Release pr-19-07

Edited by Waspie_Dwarf, 24 August 2007 - 10:54 AM.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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#5    Waspie_Dwarf

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Posted 24 August 2007 - 10:53 AM

HAWK-I Takes Off

The European Southern Observatory (ESO) press release 36-07 is reproduced below:

ESO 36/07 - Instrument Release

22 August 2007
For Immediate Release

HAWK-I Takes Off

New Wide Field Near-Infrared Imager for ESO's Very Large Telescope


Europe's flagship ground-based astronomical facility, the ESO VLT, has been equipped with a new 'eye' to study the Universe. Working in the near-infrared, the new instrument - dubbed HAWK-I - covers about 1/10th the area of the Full Moon in a single exposure. It is uniquely suited to the discovery and study of faint objects, such as distant galaxies or small stars and planets.

After three years of hard work, HAWK-I (High Acuity, Wide field K-band Imaging) saw First Light on Yepun, Unit Telescope number 4 of ESO's VLT, on the night of 31 July to 1 August 2007. The first images obtained impressively demonstrate its potential.

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The HAWK-I instrument mounted on the telescope's Nasmyth (side) port. HAWK-I is attached on Yepun, Unit Telescope number 4 of ESO's Very Large Telescope and saw First Light on the night of 31 July 2007. As the telescope tracks the celestial object under study, the entire instrument (2.2 tonnes) must rotate with great precision about its optical axis to hold the image stationary while the exposure is taken.

"HAWK-I is a credit to the instrument team at ESO who designed, built and commissioned it," said Catherine Cesarsky, ESO's Director General. "No doubt, HAWK-I will allow rapid progress in very diverse areas of modern astronomy by filling a niche of wide-field, well-sampled near-infrared imagers on 8-m class telescopes."

"It's wonderful; the instrument's performance has been terrific," declared Jeff Pirard, the HAWK-I Project Manager. "We could not have hoped for a better start, and look forward to scientifically exciting and beautiful images in the years to come."

During this first commissioning period all instrument functions were checked, confirming that the instrument performance is at the level expected. Different astronomical objects were observed to test different characteristics of the instrument. For example, during one period of good atmospheric stability, images were taken towards the central bulge of our Galaxy. Many thousands of stars were visible over the field and allowed the astronomers to obtain stellar images only 3.4 pixels (0.34 arcsecond) wide, uniformly over the whole field of view, confirming the excellent optical quality of HAWK-I.

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The figure shows the Serpens star-forming region, as it was imaged during commissioning, on HAWK-I's four large infrared detectors. The gap between them is real, and multiple exposures are required to make a filled-in picture. The colour composite was created from images taken through three filters, J, H and K.


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This image shows a close-up view of detector 1 of HAWK-I. Despite a total exposure time of only 1 minute in each of three infrared filters, the image shows great detail in this million-year old region, revealing red young stars, reflection nebulae and dark clouds of gas and dust very clearly.

HAWK-I takes images in the 0.9 to 2.5 micron domain over a large field-of-view of 7.5 x 7.5 arcminutes. This is nine times larger than that of ISAAC, another near-infrared imager on the VLT that went into operation in late 1998. ISAAC has shown how deep near-infrared images can contribute uniquely to the discovery and study of large, distant galaxies, and to the study of discs around stars or even very low mass objects, down to a few Jupiter masses.

HAWK-I will build on this experience by being able to study much larger areas with an excellent image quality. HAWK-I has four 2k x 2k array detectors, i.e. a total of 16 million 0.1 arcsecond pixels.

"Until the availability of the James Webb Space Telescope in the next decade, it is clear that 8-m class telescopes will provide the best sensitivity achievable in the near-infrared below 3 microns," explained Mark Casali, the ESO scientist responsible for the instrument.

Given the wide field, fine sampling and the high sensitivity of HAWK-I, the deepest scientific impact is expected in the areas of faint sources. "With its special filter set, HAWK-I will allow us to peer into the most distant Universe," said Markus Kissler-Patig, the Instrument Scientist. "In particular, with HAWK-I, we will scrutinise the very first objects that formed in the Universe."

HAWK-I will also be very well suited for the search for the most massive stars and for the least massive objects in our Galaxy, such as hot Jupiters. But HAWK-I will also be a perfect instrument for the study of outer Solar System bodies, such as distant, icy asteroids and comets.

HAWK-I is the eleventh instrument to be installed at ESO's VLT. It bridges the gap between the first and the second generation instruments to be installed on this unique facility.

Contacts

Mark Casali, Markus Kissler-Patig
ESO, Garching, Germany
Phone: +49 89 3200 6661, +49 89 3200 6244
Email: mcasali (at) eso.org, mkissler (at) eso.org.

Source: ESO Press Release pr-36-07

Edited by Waspie_Dwarf, 24 August 2007 - 10:55 AM.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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