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COSMOS Project Summary

COSMOS is an HST Treasury Project to survey a 2 square degree equatorial field with the Advanced Camera for Surveys (ACS). It is the largest survey that HST has ever done, utilizing 10% (640 orbits) of its observing time over the course of two years (HST Cycles 12 and 13). The project also incorporates major commitments from other observatories around the world, including the VLA radio telescope, ESO's VLT in Chile, ESA's XMM X-ray satellite, and Japan's 8-meter Subaru telescope in Hawaii. The COSMOS collaboration involves almost 100 scientists in a dozen countries.

Members of the COSMOS Collaboration

The primary goal of COSMOS is to study the relationship between large scale structure (LSS) in the universe and the formation of galaxies, dark matter, and nuclear activity in galaxies. This includes a careful analysis of the dependence of galaxy evolution on environment. The wide field of coverage of COSMOS will sample a larger range of LSS than any previous HST survey.

COSMOS will detect:

  • over 2 million objects with IAB > 27 mag
  • over 35,000 Lyman Break Galaxies (LBGs)
  • extremely red galaxies out to z ~ 5

The COSMOS field is equatorial, for easy access to telescopes in both hemispheres:

RA (J2000) = 10:00:28.6
DEC (J2000) = +02:12:21.0

Status of COSMOS: July 1, 2005

COSMOS has completed all of its HST observations. This includes two years of observations with the ACS, WFPC2, and NICMOS instruments. Currently the first cycle of observations are available through the COSMOS Archive. Additional observations, such as the Subaru optical, VLA radio, and XMM X-ray surveys of the field have also been completed. Those data will be released over the next several months. Object catalogs are also being produced, and spectral observations of objects in the field are ongoing.

The COSMOS collaboration is currently concentrating on producing the first batch of scientific papers on the survey. These papers should appear in print at the same time as the COSMOS special session at the January, 2006 AAS Meeting in Washington, D.C. Stay tuned to these web pages for future updates!