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Description
This is a compendium of 607,208 type-I QSOs and AGN, largely complete from the literature to 5-August-2017, including the release of SDSS-DR14. Also included are ~1.35M high-confidence (80%+ likelihood) quasar candidates from the NBCKDE, NBCKDE-v3, XDQSO, AllWISE and Peters photometric quasar catalogs (citations in Note 7 below) and from all-sky radio/X-ray associated objects which are calculated here. Type-II and Bl Lac objects are also included, bringing the total count to 1,998,464. Changes from version 5.1 are: (1) SDSS-DR14 and SDSS-DR14Q have been added, using the processing rules from the Half Million Quasars catalog (HMQ: Flesch 2015PASA...32...10F). (2) WISE quasar candidates have been added from Secrest et al, 2015, Cat. J/ApJS/221/12; these are ~430K candidates over the whole sky for which 2-color optical objects were found within a 2-arcsec radius. They have been processed into pQSOs from calibration against the SDSS-DR12Q multi-class superset, and photometric redshifts obtained using the four-color based method from the HMQ appendix 2. The four colors used were B-R, R-W1, W1-W2 & W2-W3. (3) Type-II narrow emission-line galaxies, (NELGs, class='N') are added as the luminosity class corresponding to the type-I AGN galaxies. High-luminosity type-II NLAGN (class='K') correspond to the type-I quasars. The NLAGN/NELG divider is the same luminosity/psf function which separates QSOs from AGNs. Type-II NELGs include unquantified contamination by LINERs and probably a few starbursts which eluded removal, so it serves as a catch-all category presented for completeness, rather than as a strict type-II class. (4) Small publications to 5 August 2017 have been added. (5) Positional fixes (of about 2 arcsec) have been applied to ~150 objects. Low-confidence or questionable objects (so deemed by their researchers) are not included in Milliquas. Additional quality cuts can be applied as detailed in Flesch 2015PASA...32...10F). Multiple lensed images are excluded and only the brightest one kept. The aim here is to present one unique reliable object per each data row. 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. This catalog can be cited as Milliquas, Flesch E., 2015PASA...32...10F which was the published version of this catalog as at 2015 after the release of SDSS-DR12. Questions/comments/praise/complaints may be directed to me at eric(at)flesch.org.
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