Veron Catalog of Quasars & AGN, 13th Edition: 168,941 Objects with Redshifts

168,941 astronomical objects, including 133,336 quasars, 1,374 BL Lac objects, and 34,231 active galaxies, comprise the 13th edition of the Veron-Cetty and Veron catalog. The NASA HEASARC created this online version in April 2010 based on tables from the CDS, with a last update in June 2012. It contains positions, redshifts, photometry (U, B, V), and radio flux densities for objects with measured redshifts known prior to July 1, 2009.

Use Cases

• Train redshift prediction models based on the provided photometric and positional data.
• Analyze the spatial distribution of quasars based on the catalog's positional coordinates.
• Study the luminosity function of active galaxies using the provided absolute magnitudes.
• Cross-match radio sources using the included 6-cm and 20-cm flux densities.

Strengths

• Contains 168,941 total objects, a significant increase from the 108,080 in the 12th edition.
• Provides absolute magnitudes calculated with a specific cosmology (H0 = 71 km/s/Mpc, q0 = 0).
• Includes multiple data types per object: positions, redshifts, photometry, and radio fluxes where available.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Excludes information on absorption lines, X-ray properties, gravitationally lensed quasars, and quasar pairs listed in separate files.
• Data freshness should be verified; the catalog includes objects known prior to July 2009 and was last updated in 2012.

Provenance

Source

NASA HEASARC, based on machine-readable tables from the CDS (catalog VII/258).

Collection Method

Compilation and update of the Veron-Cetty and Veron catalog.

Time Range

Objects with measured redshifts known prior to July 1, 2009.

Freshness

Last updated in June 2012; includes objects known prior to July 2009.

Geography

All-sky coverage.