ELVIS -
Emission-Line galaxies with VISTA Survey
ELVIS - Emission-Line galaxies with VISTA Survey |
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| ***Latest news*** Introduction ELVIS is part of the Ultra-VISTA Public Survey with the near-infrared survey telescope VISTA. The survey goals are to find a large sample of emission-line galaxies at several redshifts, thereby enabling a study of galaxy formation and evolution, the star formation history of the Universe and reionisation by the first sources of light after the 'Dark Ages'. VISTA VISTA is a 4-m. survey telescope located at Paranal in Chile.  The
project was financed by several UK institutions, including 18 UK
universities through PPARC. The
consortium was led by Queen Mary,
University of London. Upon completion, the telescope is
donated to ESO, which will manage
the
observatory and any observations made there. VISTA was intended as a
survey telescope, and for surveys the main importance is to have a
large field-of-view. Hence, the near-IR camera on VISTA has a
pawprint field-of-view of 0.6 square degrees and a mosaiced
field-of-view of 1.6 square degree.The filter wheel originally contains the five broad-band filters Y, z, J, H and Ks, and as a part of the ELVIS project the Dark Cosmology Centre has purchased a set of narrow-band filters with central wavelength 1185 nm and FWHM 10 nm. They are installed into the filter wheel since summer of 2007. The observatory is typically for surveys, hence ~75 % of its time will be used for ESO Public Surveys. These surveys will have broad science goals, with all data becoming public within six months after acquisition. ELVIS ELVIS is such an accepted survey, in which we intend to image four strips of 0.18 square degree with the narrow-band filter to a depth of a 3.7 x 10-18 erg/s/cm2. The proposed field is the COSMOS field, which contains a wealth of public data in a two square degree field and in many bands from X-rays to infrared and radio. The survey will be part of the Ultra-VISTA survey (PIs Dunlop, Le Fevre, Franx and Fynbo), including very deep broad-band (zJHKs) infrared imaging with VISTA. The science goals are to find a large sample of emission-line galaxies at different redshifts, such as H-alpha at z = 0.8, [OIII] and H-beta at z = 1.4, [OII] at z = 2.2 and Ly-alpha at z = 8.8. We expect to find thousands of H-alpha emitters, hundreds of intermediate redshift emitters and a few tens of Ly-alpha emitters. The study of the whole sample will give star formation rates and densities at discrete points in history. This will be useful in trying to pin down the star formation history of the Universe. For each sub-sample, we will also be able to answer more direct questions; e.g. what does the faint end of the luminosity function for H-alpha emitters at redshift 0.8 look like, what are the kinematics in and properties of AGN at redshift ~2, and at what redshift and by what objects was our Universe reionised? Observing plan Ultra-VISTA is delayed and will now, hopefully, start observing in ESO Period 84 (1 October 2009 - 1 April 2010) and will then observe the COSMOS field all the time it is up and our other constraints are met. That way, the program can be completed in 5 years if no unforeseen problems arise. The data in the 5 bands will be built up simultaneously. Ultra-VISTA consists of three parts; the "deep" survey, the "very deep" survey and the narrow-band survey. The "deep" survey will be slightly more shallow, in all the broad-bands and covering a full 1.6 deg2 field. The "very deep" will (as the name implies) go very deep, but only in four strip covering in total 0.9 deg2. This is also the configuration that the narrow-band survey will have. The "deep" survey is planned to be completed first. The data will be pipelined both in Cambridge (CASU/VDFS) and through the Astro-Wise and Terapix network. First release of reduced data and catalogues is expected beginning of 2011. Publications related to ELVIS & Ultra-VISTA
Latest news
For more information on the project and our science goals, please contact me (knilsson [at] eso.org)! |