XMM-Newton 2XMMi-DR3: Classifications for 4,330 X-ray Sources

NASA HEASARC provides a catalog classifying 4,330 X-ray point sources from the XMM-Newton 2XMMi-DR3 survey. The classification, based on literature and derived criteria, identifies stars, active galactic nuclei (AGNs), and compact object systems. This table was created in October 2012 from published research in The Astrophysical Journal.

Use Cases

• Classifying X-ray sources into stellar, AGN, or compact object categories based on flux ratios and variability features mentioned in the description.
• Training ML models for automated source type identification using spectral index and long-term flux variation factors.
• Studying the properties of candidate ultraluminous X-ray sources based on their described lower variability.
• Analyzing the separation criteria for stars (low X-ray-to-IR flux ratios, frequent flares) versus AGNs (consistent spectra).

Strengths

• Contains classifications for 4,330 sources with estimated false identification probabilities (1% for stars, 3% for AGNs, 18% for compact objects).
• Includes specific, quantified properties like AGN power-law photon index (1.91 +/- 0.31) and flux variation median (1.48).
• Sources were selected with a strict signal-to-noise ratio requirement (at least one detection > 20) for reliability.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is derived from a 2012 publication; newer observations may not be included.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC)

Collection Method

Classification based on literature review and derived criteria from XMM-Newton observations.

Time Range

Based on the 2XMMi-DR3 catalog observations; specific temporal coverage is not detailed.

Freshness

Last updated 2026-03-13 17:39:32.585585; freshness should be verified.

Geography

Celestial; covers point sources across the sky observed by XMM-Newton.