Cygnus OB2 Chandra X-Ray Catalog: 1696 Sources in a Massive Star-Forming Region

A catalog of 1696 X-ray sources detected in the massive star-forming region Cygnus OB2, extracted from two archival Chandra observations. The HEASARC created this table in October 2009 based on electronic versions from the reference paper. The catalog includes X-ray broad-band fluxes, spectral model fits, and optical and near-IR photometry for many sources.

Use Cases

• Analyze stellar X-ray source populations based on the catalog of 1696 objects.
• Study X-ray variability and spectral properties based on fitted thermal plasma models and analyzed light curves.
• Perform cross-wavelength matching and analysis based on optical and near-IR counterpart identifications for 1501 sources.
• Assess source authenticity and catalog reliability based on described Monte Carlo simulations and false-source probability analysis.

Strengths

• Catalog of 1696 X-ray sources, one of the largest X-ray catalogs of a single star-forming region.
• High counterpart identification rate, with 1501 (89%) sources having optical or near-IR counterparts.
• Low estimated false-source rate (<1%), with an even lower fraction for sources with optical/near-IR associations.
• Includes multi-wavelength data, with 755 (45%) objects having six-band optical and near-IR photometry.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Freshness should be verified; the underlying data is from archival observations and the catalog was created in 2009.

Provenance

Source

NASA HEASARC, based on tables from the reference paper obtained from the CDS.

Collection Method

Source extraction from two archival Chandra observations, with counterpart identification using Bayesian techniques on data from INT, 2MASS, and UKIRT surveys.

Time Range

Observational timeframe not specified; catalog created in October 2009.

Freshness

Last updated 2026-03-13 17:41:05.037746; freshness should be verified.

Geography

Cygnus OB2 star-forming region in our Galaxy.