COSMOS X-ray Group Catalog: Galaxy Groups with Mass and Redshift Estimates

A COSMOS X-ray group membership catalog combines X-ray group properties with mass estimates from weak lensing and member galaxy information. The catalog covers a 2 square degree equatorial field and includes over 2 million galaxies spanning 75% of the age of the universe. It was produced by the National Aeronautics and Space Administration and last updated in March 2026.

Use Cases

• Study galaxy group formation and evolution based on X-ray properties and weak lensing mass estimates.
• Analyze the relationship between galaxy groups and large-scale structural environment mentioned in the survey description.
• Train models to predict group properties using combined X-ray, weak lensing, and photometric redshift data.
• Investigate galaxy membership and red sequence overdensities within 500 kpc of X-ray centers.

Strengths

• Integrates data from multiple major space-based and ground-based telescopes, including Hubble, Spitzer, and Chandra.
• Covers a significant cosmic time span, with galaxies detected across 75% of the age of the universe.
• Combines three distinct data sources: X-ray group properties, weak lensing mass/radius calibrations, and member galaxy information.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is limited to groups with redshift z<1, which may exclude higher-redshift phenomena.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Combination of X-ray group properties, weak lensing mass/radius calibrations, and member galaxy information from published studies.

Time Range

Spans 75% of the age of the universe.

Freshness

Last updated 2026-03-13 20:05:34.866864; freshness should be verified.

Geography

Covers a 2 square degree equatorial field.