The Million Quasars (Milliquas) catalog, v4.4

Note: This data (except for candidates) has been published as the Half Million Quasars catalog (HMQ, 2015 PASA accepted). Please use that catalog as the citation for any research. The HMQ page is here.


MILLIQUAS v4.4 includes data up to 25 January 2015, including SDSS-DR12 and SDSS-DR12Q ( 1,151,011 total objects are displayed, including 424748 type-I QSOs from the literature, 26623 type-I AGN (like QSOs but extended, e.g., Seyferts), 612203 photometric quasars from SDSS-based NBCKDE and BOSS, and 53059 radio/X-ray associated QSO candidates. Radio and/or X-ray identifications are shown where applicable, plus, for the photometric and radio/X-ray associated candidates, the probability of each being a true quasar. The threshold for inclusion of candidates is 80% QSO-likelihood.

Quick browse of (flat text) data here , and here is the ReadMe

Get the file (40Mb with references list) here in FITS or as  flat text .



Stars & Galaxies, radio/X-ray associated.

Milliquas v4.4 was extracted from a larger database which includes stars & galaxies (and candidates for such) associated to radio/X-ray detections at 80%+ confidence. The counts are 192654 galaxies & galaxy candidates, 14574 stars & star candidates, and 102982 candidates of unclear classification although most of them will be galaxies.

I have made tables for each of these in the same layout as Milliquas, plus a table of extra references (citations) for them, all in a 12 Mb zipped file here in FITS or as flat text .

Legend of object classifications: G=galaxy, g=LRG, H=starburst, L=LINER, M=group, N=NELG,S=star, W=WD, C=CV. The percentage column shows the confidence that the radio/X-ray detection is truly associated to this object.

The Atlas of Radio/X-ray Associations (ARXA, 2010 PASA, 27, 283) is here.


Eric Flesch, last updated 24 February 2015