COSMOS X-ray Group Member Catalog: Galaxy Groups from a 2 Square Degree Survey

COSMOS is an astronomical survey probing galaxy formation across 75% of the universe's age. This catalog, from NASA, identifies group members from the COSMOS ACS galaxy catalog, with corrections for charge transfer inefficiency applied to the raw Hubble Space Telescope images. The catalog is truncated at a magnitude limit of F814W < 24.2 and excludes objects within ACS masks and bad detections.

Use Cases

• Study galaxy group membership and large-scale structure based on the catalog's group identification.
• Analyze galaxy evolution as a function of redshift and environment using the survey's cosmic time coverage.
• Investigate the impact of instrument charge transfer inefficiency corrections on galaxy detection and photometry.
• Model stellar mass distributions for galaxies within groups, leveraging the catalog's stellar mass requirement.

Strengths

• Derived from a major multi-wavelength survey (COSMOS) using data from Hubble, Spitzer, Chandra, and other major telescopes.
• Covers a 2 square degree equatorial field and includes over 2 million detected galaxies.
• Includes corrections for charge transfer inefficiency (CTI) to improve data quality from the raw ACS images.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• The catalog is truncated at a specific magnitude limit (F814W < 24.2), which may exclude fainter objects.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Group membership catalog drawn from the COSMOS ACS galaxy catalog, with CTI-corrected images.

Time Range

Spans 75% of the age of the universe.

Freshness

Last updated 2026-03-13 18:28:47.888866; freshness should be verified.

Geography

Covers a 2 square degree equatorial field.