SDSS DR6 Galaxy Clusters Catalog: 39,716 Clusters with Mass and X-ray Correlations

39,716 galaxy clusters identified in the redshift range 0.05 < z < 0.6 using photometric redshifts from the Sloan Digital Sky Survey Data Release 6. The catalog, created by NASA HEASARC in August 2009, provides richness, summed luminosity, and galaxy counts for clusters, with properties tightly related to X-ray luminosity and temperature.

Use Cases

• Training models to predict cluster mass based on richness and summed luminosity relationships described in the catalog.
• Cross-identifying optical clusters with X-ray sources, as demonstrated by the 790 new candidate X-ray clusters found.
• Studying the completeness and contamination rates of galaxy cluster detection algorithms using the provided performance metrics.
• Analyzing the scaling relations between optical properties (richness, luminosity) and X-ray observables (luminosity, temperature).

Strengths

• Contains 39,716 clusters, a substantial sample for statistical analysis.
• Cluster redshifts are estimated with an uncertainty of less than 0.022.
• Monte Carlo simulations indicate a cluster detection rate of more than 90% for massive clusters at z <= 0.42.
• Provides derived properties like richness and summed luminosity, which are tightly related to X-ray observables.

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 contamination rate of member galaxies is roughly 20%, which may affect some analyses.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), based on tables from the Astrophysical Journal.

Collection Method

Identified using photometric redshifts of galaxies from the Sloan Digital Sky Survey Data Release 6.

Time Range

Observational data from SDSS Data Release 6.

Freshness

Last updated 2026-03-13 18:57:09.216700; freshness should be verified.

Geography

Sky coverage of the Sloan Digital Sky Survey.