ROSAT All-Sky Survey: Optical Counterparts for 370 X-Ray Sources

722 possible optical counterparts for 370 X-ray point sources from two 10-degree fields in the ROSAT All-Sky Survey. The catalog was created by NASA researchers using optical variability analysis on hundreds of archival photographic plates to identify 256 probable matches, including active galactic nuclei, cataclysmic variables, and stars. The data table combines results from two fields, one at high galactic latitude and one at low galactic latitude.

Use Cases

• Training models to classify X-ray source types (e.g., AGN vs. stars) based on optical variability and positional data.
• Analyzing the correlation between X-ray emission and optical variability mentioned in the description.
• Cross-referencing astronomical catalogs using the provided optical counterpart positions and source classifications.
• Studying the distribution of different object types (like AGN and CVs) across galactic latitudes.

Strengths

• Contains 722 entries for 370 distinct X-ray sources, providing multiple candidate matches.
• Lists 256 probable optical identifications across 12 object types, including 126 active galactic nuclei and 72 new variable objects.
• Method leveraged hundreds of archival photographic plates, requiring no new telescope time.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count for the final table is not explicitly stated in the provided metadata.
• The description notes some objects may be misclassified (e.g., some AGNs may be cataclysmic variables).

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Optical identification via variability analysis on archival plates from the Sonneberg field patrol, combined with standard methods.

Time Range

Based on the ROSAT All-Sky Survey (1990s) and archival plates.

Freshness

Last updated 2026-03-13 20:06:59.161320; freshness should be verified.

Geography

Covers two 10-degree by 10-degree fields in the sky: one near 26 Com (galactic latitude b=83°) and one near gamma Sge (b=-5°).