C-COSMOS: Chandra X-Ray Point Source Catalog for the COSMOS Field

1761 X-ray point sources detected by the Chandra COSMOS Survey, a 1.8 Ms program imaging the central 0.5 deg² of the COSMOS field. The catalog was created by NASA HEASARC in 2009 based on data from the Astrophysical Journal, with sources detected at a spurious probability of < 2 x 10⁻⁵. Supporting multi-wavelength data and images are available via the COSMOS Survey website and IRSA.

Use Cases

• Cross-matching X-ray sources with optical/infrared counterparts based on the sub-arcsecond positional accuracy mentioned in the description.
• Analyzing source population statistics and flux distributions using the provided log N-log S curve and limiting flux depths.
• Studying the uniformity of X-ray exposure across the field based on the described +/-12% exposure variation in the inner area.
• Training models for X-ray source detection in overlapping tiling strategies, referencing the novel method described.

Strengths

• Large sample of 1761 reliably detected point sources with a low spurious probability (< 2 x 10⁻⁵).
• Uniform exposure coverage (+/-12%) across the inner 0.5 deg² field, leading to a sharply defined flux limit.
• Deep sensitivity with limiting fluxes of 1.9 x 10⁻¹⁶ erg cm⁻² s⁻¹ (soft band) and 7.3 x 10⁻¹⁶ erg cm⁻² s⁻¹ (hard band).
• Includes supporting multi-wavelength data and images for source identification via linked repositories.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for specific statistical analyses.
• Last updated 2026-03-13 18:12:34.618401; freshness should be verified as the underlying observations are from an earlier program.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC)

Collection Method

Observational data from the Chandra X-ray Observatory's ACIS-I imager, processed with a novel source detection method for overlapping tiles.

Time Range

null

Freshness

Last updated 2026-03-13 18:12:34.618401

Geography

Centered on the COSMOS field at RA 10 hours, Dec +02 degrees, covering 0.9 deg² total area.