Cosmic Evolution Survey

The Cosmic Evolution Survey (COSMOS) is a 2-square-degree survey, aiming to carry out the type of extensive surveying previously carried out on various small deep fields, but over a wider survey field (the COSMOS Field). The goal is observation data capable of relating the phenomena associated with individual galaxies (e.g., regarding active galactic nuclei) with phenomena evident over larger ares such as the large scale structure and the effects of dark matter. COSMOS began in 2004 with imaging of the area using Hubble Space Telescope's ACS, with sub-projects to image the area in other spectral bands and carry out spectrographic observations. Among the COSMOS-related projects:

• zCOSMOS: an ESO VLT survey using its VIMOS spectrograph on 40,000 galaxies at redshift 0.2 to 3, within the COSMOS Field, carried out between 2005 and 2010.
• C-COSMOS (Chandra COSMOS Survey): an X-ray survey of a portion of the COSMOS Field.

COSMOS2015 and COSMOS2020 are 2015 and 2020 catalogs produced from COSMOS surveys, each with on the order of a million galaxies.