ROSAT Radio-Quiet Quasars Catalog: 846 Objects with X-ray Data

846 radio-quiet quasars detected by the ROSAT satellite's All-Sky Survey or pointed observations, compiled by Yuan et al. in 1998. The catalog includes X-ray flux densities, photon indices, and absorption column densities derived from ROSAT data, with optical positions sourced from the 1993 Veron-Cetty & Veron catalog. NASA's HEASARC created this database in December 1998 based on the original publication.

Use Cases

• Correlating X-ray flux with optical quasar positions based on the catalog's cross-matched data.
• Analyzing the distribution of photon indices and absorption column densities for radio-quiet quasars.
• Identifying candidate radio-loud quasars from the 17 marked objects for further radio survey studies.
• Studying the redshift-dependent mean photon index relationship described in the source paper.

Strengths

• Contains 846 confirmed radio-quiet quasars, providing a substantial sample for analysis.
• X-ray properties like flux, photon indices, and column densities are derived from standardized ROSAT processing (SASS, RASS-II).
• Explicitly marks 17 objects identified as radio-loud from recent surveys, aiding in sample purity.

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 1990s-era ROSAT and Veron-Cetty & Veron catalogs.

Provenance

Source

NASA HEASARC, based on CDS/ADC Catalog J/A+A/330/108 (Yuan et al. 1998).

Collection Method

Compiled from ROSAT survey and pointed observation detections cross-matched with the Veron-Cetty & Veron (1993) optical quasar catalog.

Time Range

Observational data from the ROSAT mission (1990s), catalog published in 1998.

Freshness

Last updated 2026-03-13 18:36:14.883622; freshness should be verified.

Geography

All-sky coverage from the ROSAT surveys.