Status of VISTA, and Public Surveys

Abstract

VISTA is the new 4-metre wide-field survey telescope nownearing completion at ESO's Paranal Observatory.It has a single instrument, a very large near-infrared camera with a 1.65 degree diameter field, 67 Mpixels and 0.6 deg² active detector coverage. Most of VISTA's observing time will be used by six Public Surveys recently selected by ESO.Comparing to possible future surveys from Dome C,a 2.4 m class telescope at Dome C would give slightly better sensitivity than VISTA at Y, J, H bands, but would require anunrealistic number of near-IR detectors to match VISTA's field of view.In the K_dark and visible bands the comparisonis much more favourable to Dome C, so a goodstrategy for Dome C surveys is to emphasise complementarityby concentrating on the K_dark band, and i-band weak lensingsurveys.