ESO's Very Large Telescope gets new 'eye'
The European Southern Observatory (ESO) has equipped its very large telescope (VLT) with a new 'eye' to study the Universe in more depth. The scientists at the flagship facility for European astronomy designed and built HAWK-I (High Acuity, Wide field K-band Imaging) to study faint objects such as distant galaxies and small stars and planets in near infrared wavelengths. Following three years of work, the new instrument, which covers about one 10th of the area of the full moon in a single exposure, saw First Light (the first images taken with a new optical instrument) with the Yepun telescope on the night of 31 July to 1 August. According to the astronomers, these first images proved impressive and confirmed the potential of the new wide field imager. '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.' With all the instrument functions checked and confirmed as working at the performance level expected, the astronomers were able to obtain stellar images only 3.4 pixels (0.34 arcsecond) wide, uniformly over the whole field of view, thus confirming the excellent optical quality of HAWK-I. HAWK-I will take 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. As ISAAC has shown how deep near-infrared images can contribute to the discovery and study of large, distant galaxies, HAWK-I is expected to 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, meaning 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 three 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 instrument scientist Markus Kissler-Patig. 'In particular, with HAWK-I, we will scrutinise the very first objects that formed in the Universe.' HAWK-I should also be well suited in the search for the most massive stars and for the least massive objects in the Galaxy, such as hot Jupiters. It will also be a fine instrument for the study of outer Solar System bodies, such as distant, icy asteroids and comets. HAWK-I is the 11th instrument to be installed at ESO's VLT. It bridges the gap between the first and the second generation instruments to be installed on the world's most advanced optical instrument.