XMM-COSMOS: Photometric Redshift Catalog for 1,735 X-ray Sources

1735 photometric redshifts for X-ray sources detected by XMM-Newton across the 2 square degree COSMOS field. The catalog, released by NASA HEASARC in 2011, achieved an accuracy sigma[Delta-z/(1+z_spec)] ~ 0.015 with 5.8% outliers by using a large spectroscopic training set and deep H-band photometry. The study demonstrates how assumptions about source nature and the depth of available photometric bands influence redshift accuracy for active galactic nuclei.

Use Cases

• Train or benchmark photometric redshift models based on the catalog's spectroscopic training set and multi-band photometry.
• Study the properties of X-ray selected active galactic nuclei based on the catalog's classification using galaxy and AGN templates.
• Analyze the impact of photometric band depth on redshift accuracy based on the inclusion of deep H-band photometry mentioned in the description.
• Plan observational strategies for upcoming large surveys targeting AGNs based on the methodological considerations discussed.

Strengths

• Contains 1735 sources with photometric redshifts, providing a substantial sample for analysis.
• Achieved a reported accuracy sigma[Delta-z/(1+z_spec)] ~ 0.015 with a 5.8% outlier fraction for the related Chandra-COSMOS sample.
• Incorporates a large spectroscopic training set and deep H-band photometry (H_AB = 24 mag) to improve redshift quality.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown for the specific table, which may limit suitability assessment.
• Original published paper did not include positional information; coordinates were added by the HEASARC from a separate catalog.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC)

Collection Method

Derived from electronic version of Table 5 in the reference paper, with positions sourced from the XMMCOSMOS catalog.

Time Range

Observational timeframe of the XMM-Newton COSMOS survey.

Freshness

Last updated 2026-03-13 17:56:32.485511; freshness should be verified.

Geography

Covers the entire 2 square degree Cosmic Evolution Survey (COSMOS) field.