XMM-LSS: Optical Identifications for 487 X-ray Sources

The XMM-Newton Large-Scale Structure survey covers approximately 3 square degrees of sky. This table contains reliable optical spectroscopic identifications for 487 X-ray sources, increasing the number of known identifications in the field by a factor close to 5, obtained with the Anglo-Australian Telescope in 2006 and 2007. It was created by NASA HEASARC in July 2010 based on a published catalog.

Use Cases

• Classifying X-ray source types (e.g., AGN, galaxies, stars) based on spectroscopic identifications.
• Analyzing correlations between optical-to-X-ray spectral index (alpha_ox) and monochromatic luminosities for broad-line AGN.
• Studying the redshift distribution of identified sources, which spans from 0.15 to 3.87.
• Investigating ambiguous identifications where multiple optical sources correspond to a single X-ray source.

Strengths

• Contains 487 reliably identified sources from a flux-limited sample of 829.
• Provides detailed breakdowns: 265 broad-line AGN, 74 Galactic stellar sources, and 148 emission/absorption-line galaxies.
• Includes cross-matching information for 30 sources detected at radio frequencies.

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 survey field and flux limits.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC)

Collection Method

Optical spectroscopic observations with the AAOmega instrument at the Anglo-Australian Telescope.

Time Range

Observations from 2006 September 25-27 and 2007 September 11-13.

Freshness

Last updated 2026-03-13 19:36:40.591306; freshness should be verified.

Geography

Sky coverage from the XMM-LSS and CFHTLS surveys (~3 square degrees).