The Million Quasars (Milliquas) catalog

This is a compendium of 452,794 type-I QSOs and AGN, largely complete from the literature to 21 June 2016. Also included are ~900K high-confidence quasar candidates from SDSS-based photometric quasar catalogs (of 90%+ likelihood) and from all-sky radio/X-ray associated objects (of 80%+ likelihood). Type-II and Bl Lac objects are also included, bringing the total count to 1,422,219. This version is the same as v4.8 but with these changes: (1) The 3XMM-DR6 X-ray source catalog ( has been added and new X-ray associations calculated. (2) Radio/X-ray data have been reprocessed in line with that of the new Million Optical Radio/X-ray (MORX) associations catalogue, in preparation. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. Questions/comments/praise/complaints may be directed to Eric Flesch at eric(at)

Cone search capability for table VII/277/catalog (The Milliquas catalogue, V4.8 (22 June 2016))

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Metadata Access
Creator Flesch E.W.
Publisher CDS
Publication Year 2017
OpenAccess true
Contact CDS support team <cds-question(at)>
Resource Type Dataset
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy