RCW 49 Chandra X-Ray Point Source Catalog: 468 Sources in a Galactic Star-Forming Region

NASA's Chandra X-Ray Observatory catalog contains 468 X-ray point sources detected in a 36.7 ks observation of the Galactic massive star-forming region RCW 49 and its central OB association Westerlund 2. The study, conducted on 2003 August 23-24, identified optical, near-infrared, and Spitzer mid-infrared counterparts for 379 of the sources. This high-resolution imaging data resolved the Westerlund 2 association in X-rays for the first time and identified about 30 new OB star candidates.

Use Cases

• Classifying stellar populations based on X-ray luminosity and infrared counterparts mentioned in the description.
• Modeling cluster membership and structure based on X-ray surface number density profiles.
• Analyzing the spectral properties of early-type stars and Wolf-Rayet stars from their hard thermal X-ray spectra.
• Estimating distances to star-forming regions using the mean X-ray luminosity of T Tauri stars as a constraint.

Strengths

• Contains 468 X-ray sources detected with high photometric significance and a low chance of being background fluctuations.
• Integrates multi-wavelength data with optical, NIR, and MIR counterparts identified for 379 sources.
• Provides an unprecedented spatial resolution with a point-spread function radius of ~0.5" on-axis.
• Derives a loose distance constraint (2-5 kpc) and estimates a cluster radius (6'-7') based on the analysis.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Some spectral fits are noted as unreliable, serving only as rough estimates for X-ray luminosities.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Observation using the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory.

Time Range

Observation conducted 2003 August 23 UT 18:20 to August 24 UT 4:54.

Freshness

Last updated 2026-03-13 17:06:40.094157; freshness should be verified.

Geography

Field centered at (R.A., Dec.) = (10h24m00.5s, -57d 45' 18") in the equinox J2000.0, covering a 17 by 17 arcminutes region.