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Scientists to throw light on how galaxies formed in the early Universe

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23.12.2008

UK scientists, led by Dr Mark Lacy who is soon to join the University of Southampton, have been successful in obtaining one of the largest-ever awards of observing time on a space-based observatory - a total of 1400 hours on NASA's Spitzer Space Telescope. The observing time will be used to obtain a complete picture of how galaxies formed and evolved in the early Universe.

The Spitzer Extragalactic Representative Volume Survey (SERVS) aims to chart the distribution of stars and black holes from when the Universe was less than a billion years old to the present day. It will use Spitzer's Infrared Array Camera (IRAC) to make a very large map of the sky, capable of detecting extremely faint galaxies.

The combination of sensitivity of the equipment and the size of the area mapped by SERVS is unprecedented, making it likely to be the benchmark near-infrared survey for the next decade. The sensitivity means that the scientists will be able to detect moderately massive galaxies when the Universe was less than 8 per cent of its current age, while the wide area means that formation processes can be studied in the context of the underlying distribution of `dark' matter.

The sky regions in the survey were chosen to coincide with those that will be observed through deep imaging from the Herschel Space Observatory, the SCUBA-2 camera on the James Clerk Maxwell Telescope in Hawaii, and from the Vista Deep Extragalactic Observations survey (VIDEO). The combination of data from each of these facilities over a wide range in wavelength will give scientists a complete picture of how galaxies evolve, with no part of the formation process 'hidden' because of the effects of dust obscuration.

Dr Mark Lacy explains: "This mid-infrared survey fills a crucial gap in wavelength between the large near-infrared surveys being conducted by UK-based teams, and the far-infrared surveys to be conducted by Herschel and SCUBA-2. It will allow us to study the formation and evolution of massive galaxies like our own Milky Way in a truly representative volume of the Universe for the first time."
Mark, who is currently based at the California Institute of Technology, joins the University of Southampton as a Reader in extragalactic astronomy in September 2009.

Co-investigators include Duncan Farrah and Seb Oliver from the University of Sussex, and Matt Jarvis at the University of Hertfordshire. Other UK institutions involved include Oxford, Cambridge, Imperial College, Portsmouth and Durham. In all there are 47 investigators, of which 25 are from the UK.
The project also represents a success for the newly-formed South East Physics Network (SEPNET) which includes the Universities of Southampton, Sussex, Portsmouth and Oxford.

Dr Matt Jarvis, University of Hertfordshire, adds: "The combination of SERVS and VIDEO will allow us to make the definitive study of how galaxies grow over the history of the Universe. However, the major improvement over past surveys is the combination of depth and area, allowing us to carry out these studies over both the densest and sparsest regions of the Universe. This will enable us to build up a picture of how galaxy formation and evolution is affected by the environment in which the galaxies reside."

Sue Wilson | Source: alphagalileo
Further information: www.soton.ac.uk

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