M 31 Chandra HRC X-Ray Source Catalog: 166 Objects Over 2.5 Years

M31 (the Andromeda Galaxy) is the focus of this X-ray source catalog created by NASA HEASARC. The dataset contains measurements for 166 objects detected across 17 epochs of Chandra High Resolution Camera (HRC) images, covering a baseline of approximately 2.5 years. The authors cross-correlated sources with optical and radio catalogs and identified 17 likely X-ray transients.

Use Cases

• Analyzing long-term X-ray source variability based on the 17 epochs of snapshot images.
• Studying the luminosity function of X-ray sources in galactic disks and bulges based on the described power-law fits.
• Identifying and characterizing X-ray transients based on the 17 flagged sources.
• Cross-matching astronomical catalogs for multi-wavelength analysis based on the 55 sources with counterpart candidates.

Strengths

• Contains data for 166 distinct X-ray sources.
• Based on 17 observational epochs with a mean effective exposure of 17 ks.
• Sources were cross-correlated with optical and radio catalogs, identifying 55 counterpart candidates.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), based on CDS Catalog J/ApJ/609/735.

Collection Method

Data from 81 Chandra HRC-I observations were merged and sources were detected using the CIAO task wavdetect.

Time Range

Observations from November 1999 to June 2002.

Freshness

Last updated 2026-03-13 18:04:21.751775; freshness should be verified.

Geography

Covers most of the disk of the M31 (Andromeda) galaxy.