VISTA's superb deep infrared image of Hubble's COSMOS field

A new observation carried out with the VISTA telescope, built here in Oxfordshire and now operating in Chile, has given us the deepest wide-field infrared image of the Universe that will be available from the ground for some years to come... Gavin Dalton introduces the remarkable first-year Ultra-VISTA data.

VISTA is a dedicated 4m survey telescope equipped with a state-of-the-art infrared camera built locally at the Rutherford Appleton Laboratory near Didcot. The image shown represents the equivalent of a 20 night exposure in each of the three 'colours' represented, and reveals over 200,000 faint galaxies within the 1.7 degree image (roughly 8 times the angular extent of the full moon). The colours shown here are not 'true' colours as seen by the eye, but a composite image with Blue=1 micron, Green=1.3 microns and Red=2.2 microns, and the most distant sources that can be seen, which only show up in the Red image, are 25 billion times fainter than the familiar bright stars in the night sky. These faintest red sources are typically seen less than 1 million years after the Big Bang.

A visual inspection of the 400Mpix image could reveal large numbers of distant galaxy clusters, which would imply that many of these huge structures were already in place early in the history of the Universe. Stay tuned for the analysis!

You can read more about the Ultra-VISTA survey image in the ESO press release, and about the telescope itself here.