Milliquas million quasars catalogue

The million quasars (Milliquas) catalogue, version 3.3 (2013)

MILLIQUAS v3.3 includes data up to 6 April 2013, including SDSS-DR9. 1,246,268 objects are displayed, including 234554 QSOs from the literature (type I only), 21391 AGN (ie, Seyferts for which the integrated disk outshines the core), 1763 Bl Lacs, 912702 photometric quasars (primarily from SDSS-based NBCKDE and BOSS), and 75858 radio/X-ray associated QSO candidates. A radio and/or X-ray identification is shown where applicable, plus, for the photometric and radio/X-ray associated objects, the probability of each being a true quasar. These expected yields total to 1,124,187 quasars, making MILLIQUAS a true million-quasar catalog.

Here is the ReadMe for the catalog, which gives details, file layout and references for the source data. Appendix A of the ReadMe gives details of the photometric selection and processing.

Quick browse of sample data here

Get the file (26 Mb zipped) here: download milliquas.zip

Stars & Galaxies: Milliquas is extracted from a larger database which includes stars & galaxies which are radio/X-ray associated to a confidence of 80%+. These are presented below with the same file layouts as Milliquas. No documentation, but the citations are given in the Milliquas & ARXA ReadMe's.

Stars: get 10,328 nominally radio/X-ray associated stars here. Stars rarely are significant radio emitters, so note that this catalog's "stars" which show radio detections are likely not to be stars after all, or closely juxtaposed to an unseen background object.

Galaxies: get 182,872 radio/X-ray associated galaxies here. Types are G=galaxy, g=LRG, H=starburst, K=type 2 Seyfert/QSO, L=LINER, M=group, N=NELG.

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

Eric Flesch, last updated 6 April 2013