HRC: Optical Identifications for 5,341 High-Galactic Latitude X-ray Sources

5,341 X-ray sources from the ROSAT Bright Source Catalog at high-galactic latitude are matched with optical counterparts using digitized Schmidt plates. The catalog, produced by NASA HEASARC in 2005, provides identifications for 82% of the sources, with AGN representing the largest group at ~42%. It has been used to select complete samples of various classes of X-ray emitters.

Use Cases

• Classify X-ray emitter populations based on the reported ~42% AGN, ~31% stellar, ~4% galaxy, and ~5% cluster composition.
• Study source identification completeness and failure rates based on the 82% identification success and ~3% with no visible optical counterpart.
• Select samples for follow-up studies based on the catalog's use for creating complete samples of X-ray emitter classes.

Strengths

• Covers ~10,000 square degrees of the sky with a defined selection (|b| >= 30 degrees, Dec >= 0 degrees).
• Provides optical identifications for 82% of the 5,341 selected X-ray sources.
• Includes specific limiting magnitudes (18.5 and 20) for the optical survey plates used.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect temporal bias inherent to the 2005 production date and the underlying ROSAT survey.

Provenance

Source

NASA HEASARC, based on the CDS Catalog table J/A+A/406/353/optical.dat.

Collection Method

Optical identification using blue Schmidt prism and direct plates from the Hamburg Quasar Survey, digitized for analysis.

Time Range

Based on the ROSAT All-Sky Survey (RASS) data.

Freshness

Last updated 2026-03-13 18:30:06.767328; freshness should be verified.

Geography

Sky coverage with galactic latitude |b| >= 30 degrees and declination Dec >= 0 degrees.