XMM-LSS: 4,206 X-ray Sources with Optical Counterparts and Redshifts

The XMM-Large Scale Structure survey contains more than 6,000 X-ray point-like sources detected by the XMM-Newton Observatory over 11.1 square degrees. This table provides spectroscopic and/or photometric redshifts for 4,206 of these X-ray selected sources which have optical counterparts and have been classified by the authors. The table was created by the HEASARC in September 2013 based on a CDS catalog.

Use Cases

• Classifying X-ray sources (e.g., AGN vs. galaxies) based on spectra, spectral energy distributions, and X-ray luminosities as described.
• Investigating the correlation between X-ray source type and local galaxy overdensity as mentioned in the environmental analysis.
• Analyzing the redshift evolution of galaxy overdensities around different classes of AGN (hard vs. soft) as referenced in the findings.
• Estimating photometric redshifts using multi-band photometry (4-11 bands) for sources with optical counterparts.

Strengths

• Covers a significant survey area of 11.1 square degrees with over 6,000 detected X-ray sources.
• Provides redshift estimates for 4,435 classified sources, with a reported photometric redshift accuracy of sigma[Δz/(1+z_sp)] = 0.076.
• Includes multi-wavelength counterpart data from optical (CFHTLS), infrared (SWIRE, UKIDSS), and ultraviolet (GALEX) surveys.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count for the specific table is unknown, which may limit suitability assessment.
• Data freshness should be verified; the underlying catalog was created in 2013.

Provenance

Source

National Aeronautics and Space Administration (NASA), HEASARC, based on CDS Catalog J/A+A/557/A81.

Collection Method

Observational data from the XMM-Newton Observatory, cross-matched with optical and other multi-wavelength surveys.

Time Range

Observational period not specified; catalog created September 2013.

Freshness

Last updated 2026 -03-13 19:11:20.661281; freshness should be verified.

Geography

Covers the XMM-LSS field, an extragalactic survey region.