2XMMi/SDSS: 145 X-ray Galaxy Clusters with Spectroscopic Redshifts

145 X-ray selected galaxy groups and clusters with spectroscopic redshift measurements, extending a previous survey by 67 new optically confirmed systems. The data results from cross-matching serendipitous X-ray sources from the 2XMMi-DR3 catalog with optical data from the Sloan Digital Sky Survey (SDSS-DR10). NASA HEASARC created this table in July 2014 based on a published catalog.

Use Cases

• Train cluster detection algorithms based on X-ray and optical cross-matching methodology.
• Validate photometric redshift estimates using the provided spectroscopic redshift measurements.
• Study the relationship between X-ray luminosity and cluster mass based on the estimated parameters.
• Analyze spatial distribution and member counts of galaxy clusters using parameters like num_spect_members and spatial_offset.

Strengths

• Provides spectroscopic confirmation for 78 clusters that previously had only photometric redshifts.
• Includes 67 newly optically confirmed clusters, with 55 being newly X-ray discovered.
• Cross-correlation with other catalogs validated 264 systems with available redshifts.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect observational bias inherent to the specific X-ray and optical survey footprints.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), based on CDS catalog J/A+A/564/A54.

Collection Method

X-ray cluster candidates selected from the 2XMMi-DR3 catalog, with spectroscopic galaxy data from SDSS-DR10, using a custom algorithm for identification and redshift constraint.

Time Range

Observational data up to redshift z ~ 0.79.

Freshness

Last updated 2026-03-13 19:22:38.546736; freshness should be verified.

Geography

Sky footprint of the Sloan Digital Sky Survey (SDSS-DR7).