MILLIQUAS - Million Quasars Catalog, Version 3.7 (26 November 2013)
This version has the following changes from the previous edition:
(1) Quasar data brought up to publications as at 26 November 2013, including the SDSS DR10Q release by Isabelle Paris et al, 2013 arXiv:1311.4870. (2) 318 SDSS "quasars" of auto-redshift>4 which were not subsequently confirmed by visual inspection are removed as bogus (communication Adam Myers). (3) The Veron quasar catalog v13 (2010 A&A,518A,10) flagged some objects as questionable, "?" in their spec field. These have unclear spectra or are described as "possible" by their discovery papers. 178 of these are removed, and 52 such Bl-Lacs with redshift>0.5 are re-classed to AGNs. (4) Some positional fixes and de-duplications of individual objects.
The contents are relatively simple, each object is shown as one entry with the sky coordinates, its name, red and blue optical magnitudes, PSF class, redshift, and the source catalog for its name and redshift, plus a radio and/or X-ray identifier where applicable.
The author's current plans are to keep this updated as a "living" QSO catalog, with a view to publishing a half-million confirmed quasars catalogue in 2015.
Questions/comments/praise/complaints may be directed to Eric Flesch at firstname.lastname@example.org. He requests that, if you use this catalog in published research, that you please add a small mention (acknowledgment).
This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
This research has also made use of data obtained from the Chandra Source Catalog, provided by the Chandra X-ray Center (CXC) as part of the Chandra Data Archive.
Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy. The SDSS-III web site is http://www.sdss3.org/.
0.1 22Apr09 0.3 6May09 Added a radio identifier and an X-ray identifier. 0.5 11May09 Added 30816 objects from newly calculated associations to XMM, Chandra and SUMSS detections, plus some tweaks. Also added QSO probability % for non-confirmed QSOs. 0.8 22Jun09 Added Chandra Source Catalog 1.0 (2009). 1.0 03Aug09 Extensive de-duplication. XMM Slew Catalog data added. 1.4 20Aug09 Misc fixes in the de-duplications. 1.5 29Aug09 Used XMM Slew Catalog v1.3 2.0 14Jun10 Used XMM Slew Catalog v1.4, XMM3, and XAssist4. 2.1 17Aug10 Removed 8627 NELGs masquerading as AGNe. 2.2 7Jan11 About 10,000 AGNe from the previous edition are now presented as QSOs. 796 AGNe mistakenly expunged in 2.1 have been restored. 2.3 5Mar11 SDSS DR-8 and BOSS targets have been included and the threshold for inclusions of candidates has been raised from 60% to 70%. 2.4 5Jun11 Improved QSO-likelihood calculation for the BOSS targets, so 17% of previously included BOSS targets drop out. Newly included data from several sources (see above). 2.5 20Jul11 Some de-duplication of quasars which were discovered prior to 1990, 200 recent NED quasars added, some radio/X-ray associations to USNO-B optical data added. 2.6 10Sep11 The USNO-B catalog has been added and hard-deduplicated against APM and SDSS data to make a background pool of 1.04 billion optical objects. Also, about 12 million orphaned one-color APM objects have been removed. There are consequently improvements in this catalog's optical selections and astrometry without changing the net totals much. XMM Slew 1.5 catalog added. Some further astrometric fixes and de-duplications of early quasars. 2.7 5Nov11 New quasar publications to 4 November 2011 were added, and a few fixes on individual objects incorporated. 2.8 29Jan12 Completed the fixes of non-astrometric relic data from the Veron-Cetty & Veron 13th edition. About 150 other fixes. Quasars compilation updated through 27 January 2012. 2.9 2Apr12 Data brought up to publications as of 31 March 2012, about 50 astrometric fixes done, and the new FIRST radio catalog, 12Feb16 version, incorporated. 2.10 6Aug12 Data brought up to publications as of 31 July 2012, including the SDSS-DR9 release, XAssist XMM-Newton and Chandra X-ray data updated to 30 June 2012; as this is a catalog for type I (broad-line) objects, 1870 Seyfert-2s, 532 LINERs, and 6 NELGs were removed, but Bl Lacs were retained as unconstrained emission objects. 3.0 9Sep12 Data brought up to publications as of 31 August 2012. Redshifts are calculated for the XDQSO photometric quasar candidates. Fixed issues with 30 DEEP2 object. Separated out 15 SDSS-DR9 object that had been conflated with others. QSO-AGN separator restored to that used through v2.9, thus ~5000 QSOs were re-classified as AGNe. AGNe historic names sourced from the Principal Galaxy Catalogue. 3.1 22Oct12 Quasar data brought up to publications as of 20 Oct. 2012, including the new DR9 Quasar catalog (Paris I., 2012, arXiv:1210.5166). 3.2 10Feb13 Quasar data brought up to publications as of 9 Feb. 2013. MMT quasar positions fixed, and made a few small miscellaneous fixes. 3.3 7Apr13 Quasar data brought up to publications as at 6 April 2013. Added 713 new quasars from Palanque-Delabrouille et al. (2013, A&A, 551, A29). Included SWIRE data, consisting of 117 confirmed quasars and >20K photometric quasars from Rowan-Robinson et al. (2013, MNRAS, 428, 1958). Located 8 QSOs that were previously uncertainly located and removed 1 that had no credible candidates. Removed 26 SDSS-DR9 quasars after inspection showed they were only artifacts. Removed 144 questionable quasars from Iovino et al. (1996, A&AS, 119, 265). Removed 8 blazars classified as white dwarfs by the SDSS DR7 WD Cat (2013,ApJS,204,5). Miscellaneous: 4 moves, 2 de-dups, and 4 deletions found after extensive trawling. 3.4 11Jul13 Quasar data brought up to publications as at 11 July 2013. The author's paper (2013,PASA,30,4) marked 9 QSOs as uncertainly located. Of those: (a) Q 0112-27 is finally sited at J011517.2-271223, courtesy Cyril Hazard. (b) Q 0752+617 is moved to J075646.6+613639, r=16.9, b=17.4, as a better fit with its co-published quasar (NOTNI 16, r=16.7, b=17.2). Added 92 new quasars from Cyril Hazard. Q 1409+732 was found to be sited on a plate flaw, and is now moved one arcmin due East to perfect optical fit at J141003.2+725939, r=19.3, b>22. XAssist v4 XMM-Newton & Chandra X-ray data updated to 30-June-2013. 3.5 11Aug13 Quasar data brought up to publications as at 10 August 2013, including SDSS-DR10. Note that the DR10 is an automated catalog, so its object classifications are not as trustworthy as manual classifications. Thus, earlier manual classifications are retained over DR10 classifications. XMM-Newton X-ray data updated to 3XMM-DR4 version (24-July-2013). FIRST radio data updated to 13Jun05 version (05-June-2013). 3.6 23Oct13 Quasar data brought up to publications as at 22 October 2013. Two additional columns of radio/X-ray detections were added. This is so that any radio lobes will always be fully displayed, and extra detections from other source catalogs give a sense of fuller coverage. 158 additional quasars were added from SDSS-DR10. These were flagged as bad astrometry, but they are confirmed by the author's optical background database. Photometric quasar candidates from surveys other than NBCKDE and XDQSO, e.g., SWIRE, have been dropped because much of their yield are type 2. This includes Palanque-Delabrouille et al. (2011,A&A,530,122), which has been well investigated spectroscopically and its residue thus less likely to be QSOs. X-ray detections from the Champ2 catalog, Kim M. et al, 2007,ApJS,169,401 have been removed. It's a small catalog which, unlike others, does not present its raw astrometry needed for calculating optical solutions. The Veron quasar catalog v13 (2010 A&A,518A,10) included some objects denoted as non-quasars by their discovery papers, and the following have been removed as a result: (a) 484 emission-line galaxies (ELGs) of z<0.46 from Schneider/Schmidt/Gunn 1994,AJ,107,1245, incorporated as QSOs by VCV13; (b) 55 ELGs of Schneider/Schmidt/Gunn 1999,AJ,117,40; (c) 58 galaxies from 2dF-GRS (Colless M. et al., astro-ph/0306581); and (d) 41 galaxies from La Franca F. et al., 1999,A&AS,140,351. A few positional fixes, de-duplications, and removals of type-2s. 3.7 26Nov13 See list of changes above.
Flesch, E. The Million Quasars (MILLIQUAS) Catalog, Version 3.7 (26 November 2013) http://quasars.org/milliquas.htmSee also:
APM Catalog http://www.ast.cam.ac.uk/~apmcat USNO-A/B Catalogs http://www.nofs.navy.mil NVSS Catalog http://www.cv.nrao.edu/nvss FIRST Catalog http://sundog.stsci.edu SUMSS Catalog http://www.physics.usyd.edu.au/sifa/Main/SUMSS MGPS Catalog http://www.physics.usyd.edu.au/sifa/Main/MGPS2 ROSAT Catalogs http://www.mpe.mpg.de/xray/wave/rosat/catalogue http://www.mpe.mpg.de/xray/wave/rosat/rra/ 1WGA Catalog http://wgacat.gsfc.nasa.gov/wgacat/wgacat.html Chandra Source Catalog http://cxc.cfa.harvard.edu/csc/ XAssist Home Page http://xassist.pha.jhu.edu/zope/xassist XMM-Newton Catalog http://xmmssc-www.star.le.ac.uk XMM-Newton Slew Survey http://www.star.le.ac.uk/~amr30/Slew
(1) pQSO, the probability that the candidate is a true QSO.
NBCKDE compares QSO & star density profiles per object to obtain a nominal pQSO. XDQSO is annotated with a nominal pQSO which their paper cautions is just a comparative figure and not a genuine QSO likelihood (see esp. their figure 14).
In this "Million Quasars" catalog, the requirement is to display genuine odds for each candidate that it is indeed a quasar. The author (Eric Flesch) accordingly analyzed the photometric candidates using techniques similar to the QORG (Flesch & Hardcastle 2004,A&A,427,387) processing. This uses a 4-color binned training set "flooded" with 10,000,000 anonymized XDQSO stars to calculate pQSOs. These were then used to adjust the NBCKDE & XDQSO nominal pQSOs into the "genuine" pQSOs reported here.
The SDSS-DR9 presents 31,007 typed objects which were previously listed as BOSS photometric quasars in Milliquas v2.9. Comparing the QSO-pcts reported there with those DR9 BOSS results yields:
QSO-pct are total hit bin by 5 QSOs objs pct -------- ----- ----- ---- 70-72 2123 2427 87.5 75 3355 3801 88.3 80 5789 6311 91.7 85 5634 6089 92.5 90 5327 5721 93.1 95 4709 4968 94.8 98-100 1678 1690 99.3 ------- ----- ----- ---- total 28615 31007 92.3Thus, the QSO yield is higher than this catalog's QSO-pcts, and true pQSO is underreported by about half. It seems a 5M "flood" should have been used instead of 10M. However, the resultant over-performing QSO-pcts enables confident use of the candidates presented in this catalog. The author plans to re-calibrate these percentages against the confirmed findings of SDSS-DR10Q (2013 Paris et al).
(2) photometric redshifts.
NBCKDE provides photometric "most likely" redshifts as the weighted average of a bounded range for each candidate. SWIRE also provides photometric redshifts via a multi-wavelength algorithm. XDQSO has not published redshifts, so these have been calculated using a training set of 199751 quasars from SDSS-DR9, binning the 4 colors by 0.1z, then using rainflow analysis to cluster the redshift bins for each XDQSO candidate. The outcome is similar to NBCKDE redshifts, and a comparison of 34035 NBCKDE & Milliquas & SDSS-DR9 QSO redshifts are listed at http://quasars.org/docs/NBCKDE-MQ-redshifts.txt , which treats each photometric redshift as a "hit" if within 0.5z of the true spectral redshift.
There it is seen that the NBCKDE hit rate is 25093/34035 = 73.7%, and the Milliquas hit rate is 25599/34035 = 75.2%. No doubt the NBCKDE method is better than this simple algorithm, but the author had the advantage of the very large SDSS-DR9 training set. This good performance validates the inclusion of these redshifts.
The designation of the source as taken from the literature. A "BOSS" prefix indicates an XDQSO BOSS target (XDQSO good=0). An "XDQ" prefix is an XDQSO non-BOSS object (XDQSO good=1,2). The name is left blank if the object is only a radio/X-ray associated object. If needing a designation for it, use the ref_name parameter and the J2000.0 equatorial coordinates to make an IAU-style name: catalog QO=QORG, AX=ARXA, MQ=MQ. For example: a source at 00 00 01.6 -25 17 07 with ref_name of 'AX' would be 'ARXA J000001.6-251707'.
The Right Ascension of the quasar candidate in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 seconds of time in the original table.
The Declination of the quasar candidate in the selected equinox. This was given in J2000.0 coordinates to a precision of 1 arcsecond in the original table.
The Galactic Longitude of the quasar candidate.
The Galactic Latitude of the quasar candidate.
The classification of the object, where the following abbreviations are used:
Q = QSO from the literature, broad-line unresolved. 309,525 of these. A = AGN, QSO-like but integrated disk outshines core. 21,728 of these. B = Bl Lac object, 1573 of these. q = photometric SDSS-based quasars, 858,191 of these. R = Radio association displayed. X = X-ray association displayed. 2 = Double radio lobe declaration (by data-driven algorithm).
The red optical magnitude of the object. The type and source of this magnitude is specified in the optical_flag parameter value. Optical data are from the APM (http://www.ast.cam.ac.uk/~apmcat/), USNO-A & USNO-B (http://www.nofs.navy.mil/), and the SDSS (http://sdss3.org/). Magnitudes have been recalibrated from the original APM/USNO-A values (which are POSS-I or UKST identified in the description for the optical_flag parameter) as documented in QORG. Calibrated USNO-A magnitudes are often retained in preference to USNO-B. APM galaxies brighter than 17th magnitude are usually represented as far too bright due to PSF modelling. If the optical_flag parameter value contains r/b/g/i/v/u/z, then the magnitudes are from the object's source catalog, e.g., SDSS, 2QZ, etc. Note that many SDSS magnitudes are extinction-corrected ~0.3 mag brighter.
The blue optical magnitude of the object. The type and source of this magnitude is specified in the optical_flag parameter value. Optical data are from the APM (http://www.ast.cam.ac.uk/~apmcat/), USNO-A & USNO-B (http://www.nofs.navy.mil/), and the SDSS (http://sdss3.org/). Magnitudes have been recalibrated from the original APM/USNO-A values (which are POSS-I or UKST identified in the description for the optical_flag parameter) as documented in QORG. Calibrated USNO-A magnitudes are often retained in preference to USNO-B. APM galaxies brighter than 17th magnitude can be represented as far too bright due to PSF modelling. If the optical_flag parameter value contains r/b/g/i/v/u/z, then the magnitudes are from the object's source catalog, e.g., SDSS, 2QZ, etc. Note that many SDSS magnitudes are extinction-corrected ~0.3 mag brighter.
This field contains coded information on the optical source properties, as follows:
p = optical magnitudes are POSS-I O (violet 4100A) and E (red 6500A). These are preferred because O is well-offset from E, and these plates were always taken on the same night, thus the red-blue color is correct even for variable objects. j = blue magnitude is SERC J (Bj 4800A blue-green) from the POSS-II or UKST surveys. Red-blue color can be suspect because the plates were taken in different epochs, i.e. years apart. g = blue magnitude is SDSS green 4900A. u = blue magnitude is SDSS ultraviolet 3850A. b = blue magnitude is Vega 4400A. i = red magnitude is infrared. v = red magnitude is visual, i.e., white. z = red magnitude is far-infrared z. (not i/v/z) = standard red color 6500A. + = variability nominally detected for both red & blue. m = proper motion nominally detected. ? = astrometry/photometry is estimated.
A coded representation for the point spread function (PSF) of the optical source in the red. The APM, USNO-B, and SDSS provide PSF class, albeit using different criteria. The codes are as follows:
- = point source / stellar PSF (APM notation: -1, here truncated) 1 = fuzzy / galaxy shape (APM notation: 1 and some 2) n = no PSF available, whether borderline or too faint to tell, etc. x = not seen in this color (fainter than plate depth, or confused, etc.)
A coded representation for the point spread function (PSF) of the optical source in the blue. The APM, USNO-B, and SDSS provide PSF class, albeit using different criteria. The codes are as follows:
- = point source / stellar PSF (APM notation: -1, here truncated) 1 = fuzzy / galaxy shape (APM notation: 1 and some 2) n = no PSF available, whether borderline or too faint to tell, etc. x = not seen in this color (fainter than plate depth, or confused, etc.)
The redshift of the object, taken from the literature as specified in the ref_redshift parameter. Photometric most-likely redshifts are rounded here to 0.1 z. The photometric redshifts provided by this catalog are discussed in the Section "Inclusion of SDSS Photometric QSO Candidates into MILLIQUAS" above.
The literature reference (with counts of name and redshift in parentheses) from which the name was taken, using the following abbreviations:
2d (91,5): 2dF GRS, Colless M. et al, 2001,MNRAS,328,1039 2L (308,95): 2LAC, Ackermann M. et al, 2011,ApJ,743,171 2Q (22747,19396): 2QZ, Croom S.M. et al, 2004,MNRAS,349,1397 2S (7972,6926): 2SLAQ, Croom S.M. et al, 2009,MNRAS,392,19 6d (22,58): 6dF Galaxy Survey, Jones D.H. et al, 2009,MNRAS,399,683 6Q (263,262): 6QZ, same attribution as 2QZ AE (16,16): AEGIS, Yan R. et al, 2011,ApJ,728,38 AL (1,1): ALHAMBRA, Matute I. et al, 2013,arXiv:1307.5117 AT (68,69): ATLAS, Mao M. et al, 2012,MNRAS,426,3334 AX (14531,0): Atlas of Radio/X-ray Associations, Flesch E.,2010,PASA,27,283 BF (28,12): BFOSC bright QSOs, Wu X.-B. et al, 2012,arXiv:1207.0204 Bu (4,4): Burbidge E.M., October 2003, Keck-I LRIS, unpublished. BZ (109,185): BZCAT v4.1.1, Massaro E. et al, 2012, www.asdc.asi.it/bzcat CB (2,2): Chandra binaries, Green P. et al, 2011,ApJ,743,81 CF (9,9): CFHIZQ, Willott C. et al, 2010,AJ,139,906 Ch (97,98): ChaMP AGN, Trichas M. & Green P. et al, 2012,ApJS,200,17 CL (8,47): CLASS Bl Lacs, March M.J.M. & Caccianiga A.,2013,MNRAS,430,2464 CO (23,22): COSMOS hi-z, Masters D. et al, 2012,ApJ,755,169 CQ (23,16): Red QSOs, Fynbo J. et al, 2013,ApJS,204,6 CW (7,0): Case low-dispersion survey, Pesch P. et al, 1985-1995 misc publ. DE (1435,1432): DEEP2 Redshifts DR4, http://deep.berkeley.edu/DR4/home.html DP (2,136): Double-Peaked NELGs, Ge J.-G. et al, 2012,ApJS,201,31 EC (7,7): E-CDFS radio, Bonzini M. et al, 2012,ApJS,203,15 F2 (21,20): FIRST-2MASS red quasars, Glikman E. et al, 2012,ApJ,757,51 FE (21,21): Faint End of QLF, Glikman E. et al, 2010,ApJ,710,1498 GA (1,1): Giant Arcs sextuple, Dahle H. et al, 2012,arXiv:1211.1091 GR (7,23): Gamma-ray Bl Lacs, Shaw M.S. et al, 2013,ApJ 764,135 GS (14,15): GOODS-SOUTH,Villforth/Sarajedini/Koekemoer,2012,MNRAS,426,360 HA (7,0): Halton Arp, misc. publications HB (42,29): Hewitt A., Burbidge G., 1989,ApJS,69,1 HC (8,8): HST-COS, Rao S. et al, 2013,MNRAS,432,866 HR (56,56): High Redshift Stripe 82,McGreer I.D. et al,2012,ApJ,768,105 HS (3,2): Herschel-SPIRE, Casey C.M. et al, 2012,ApJ,761,139 HZ (92,85): Cyril Hazard, 2013, in preparation. I9 (7,8): Integral IX, Masetti N. et al, 2012,A&A,538,123 IA (11,11): Integral X, Masetti N. et al, 2013,arXiv:1307.2898 IB (11,11): INTEGRAL/IBIS AGN, Malizia A. et al, 2012,MNRAS,426,1750 IC (33,35): ICRF South, Titov O. et al, 2011,AJ,142,165 IZ (1,1): Polsterer K., Zinn P.-C. & Gieseke F., 2013,MNRAS,428,226 KA (3,3): Kepler quasars, Mushotzky R. et al, 2011,ApJ,743,12 KB (12,12): Kepler blue H excess, Scaringi S. et al, 2013,MNRAS,428,2207 KE (5,2): KEYFIELD, Anderson M. & Filipovic M., 2009,SerAJ,179,7 KH (14,14): Harris K.A., thesis, 2012,PhDT,15 (arXiv:1201.5746) KX (274,214): KX quasars, Maddox N. et al, 2012,MNRAS,424,2876 L1 (8,8): LAMOST commissioning, Wu X.-B. et al, 2010,RAA,10,745 L2 (520,518): LAMOST Andromeda pilot, Huo Z.-Y. et al, 2013,AJ,145,159 LC (6,6): Lopez-Corredoira M. et al, 2008,A&A,480,61 LM (142,136): LMC Magellanic, Kozlowski S. et al, 2012,ApJ,746,27 LO (10,10): LOCUSS, Haines, C.P. et al, 2012,ApJ,754,97 MA (61,62): MASIV, Pursimo T. et al, 2013,ApJ,767,14 MB (709,696): MMT-BOSS, Palanque-Delabrouille N. et al, 2013,A&A,551,A29 MG (543,574): Magellanic Quasars, Kozlowski S. et al, 2013,arXiv:1305.6927 MM (174,173): MMT-BOSS pilot, Ross N.P. et al, 2012,ApJS,199,3 MQ (46201,343575): MILLIQUAS, original data in this catalog. Flesch E.,2013 NB (503652,503014): NBCKDE, Richards G.T. et al, 2009,ApJS,180,67 NE (975,308): NASA/IPAC Extragalactic DB, http://ned.ipac.caltech.edu PB (14,28): Palermo Swift/BAT, Parisi P. et al, 2013,arXiv:1311.1458 PG (4020,4): Principal Galaxy Catalogue, Paturel G. et al, 2003,A&A,412,45 PS (1,1): Pan-Starrs hi-z, Morganson E. et al, 2012,AJ,143,142 QO (21609,0): QORG, Flesch E. and Hardcastle M., 2004,A&A,427,387 QP (54,54): QPQ6, Prochaska J.X. et al, 2013, arXiv:1308.6222 QQ (2,2): QQQ Triplet, Farina E.P. et al, 2013,MNRAS,431,1019 S2 (120,124): Southern 2MASS AGN using 6dF, Masci F. et al,2010,PASA,27,302 S3 (2889,4670): SDSS Data Release 1 to 3 AGN (combined files) S4 ( 786,1429): SDSS Data Release 4 increment AGN S5 ( 781,1443): SDSS Data Release 5 increment AGN S6 ( 979,1638): SDSS Data Release 6 increment AGN S7 (2060,3085): SDSS Data Release 7 increment (incl special & extra) AGN S8 (5048,2806): SDSS DR8, Aihara H. et al, 2011,ApJS,193,29 S9 (79088,4464): SDSS DR9 AGN, Ahn C.P. et al, 2012, http://sdss3.org/dr9 SA (71606,4954): SDSS DR10, 2013, http://sdss3.org/dr10 SL (33,32): SDSS Lens Search, Inada N. et al, 2012,AJ,143,119 SM (29,29): SMC Magellanic, Kozlowski S.,Kochanek,Udalski, 2011,ApJS,194,22 SN (2897,88569): SDSS DR9Q visual, Paris I. et al, 2012,A&A,548,66 SP (153,151): SDSS DR5Q visual, Schneider D. et al, 2007,AJ,134,102 SQ (100023,97497): SDSS DR7Q visual, Schneider D. et al, 2010,AJ,139,2360 SR (24,20): SDSS Radio, McGreer I., Helfand D., White R., 2009,AJ,138,1925 ST (4042,71566): SDSS DR10Q visual, Paris I. et al, 2013,arXiv:1311.4870 SW (117,117): SWIRE, Rowan-Robinson M. et al, 2013,MNRAS,428,1958 SX (13,14): Subaru-XMM Deep, Hiroi K. et al, 2012,ApJ,758,49 UF (6,6): UKIDSS-FIRST, Glikman E. et al, 2013,arXiv:1309.6626 UL (1,1): ULAS hi-z, Mortlock D. et al, 2011,Nature,474,616 UR (6,6): UKIDSS red QSOs, Banerji M. et al., 2012,MNRAS,427,2275 UV (2,2): UVEX survey, Verbeek K. et al, 2012,MNRAS,426,1235 VE (19732,16838): Veron 13th ed, Veron-Cetty M. & Veron P., 2010,A&A,518,10 VH (2,2): VISTA-WISE Hyperluminous, Banerji M. et al, 2013,MNRAS,429,55 VK (3,3): VIKING hi-z, Venemans B.P. et al, 2013,arXiv:1311.3666 VL (168,98): VLT-LBG, Crighton N. et al, 2011,MNRAS,414,28 W2 (12,16): WISE-2MASS-RASS, Edelson R. & Malkan M., 2012,ApJ,751,52 WD (4,0): redshift, but claimed by SDSS DR7 White Dwarf cat,2013,ApJS,204,5 WE (41,0): Weedman D., 1985,ApJS,57,523 WI (3,3): WISE-selected, Stern D. et al, 2012,ApJ,753,30 WR (5,5): Wolf-Rayet QSOs, Neugent K. & Massey P., 2011,ApJ,733,123 and Neugent K., Massey P., Georgy C., 2012,ApJ,759,11 XB (131,132): XBSS, Caccianiga A. et al, 2008,A&A,477,735 XC (105,121): XMM-COSMOS, http://www2011.mpe.mpg.de/XMMCosmos/xmm53_release XD (354514,1): SDSS-XDQSO, Bovy J. et al, 2011,ApJ,729,141 XL (223,193): XMM-LSS sources, Stalin C.S. et al, 2010,MNRAS,401,294 XM (157,159): XMSS, Barcons X. et al, 2007,A&A,476,1191 XU (2,2): XMM Cluster survey, Hilton M. et al, 2010,ApJ,718,133 XW (400,417): XWAS, Esquej P. et al, 2013,arXiv:1302.5329 YF (6,4): YFOSC hi-z, Wu X.-B. et al, 2012,RAA,12,1185 Zw (4,5): the Updated Zwicky Catalog, Falco E.E. et al, 1999,PASP,111,438
The literature reference for the redshift (with counts of name and redshift in parentheses), using the same abbreviations as used for the ref_name parameter (q.v.).
The nominal probability that this object is a QSO, in percent, based on either photometric or radio/X-ray association analysis. Note that this object may be a catalogued QSO in which case this "nominal" figure is superseded. 940,535 objects without spectroscopic confirmation are included where of >=70% probability. Two families of calculated objects are included:
(1) Photometric quasars, mostly from the SDSS-based NBCKDE/XDQSO catalogs, totalling 858,191 of which ~35,000 also show radio/X-ray association. The displayed probability of NBCKDE/XDQSO objects is NOT from their catalogs which provide data ratios only; instead, the displayed absolute probability is calculated as described in the Section "Inclusion of SDSS Photometric QSO Candidates into MILLIQUAS" above.
(2) Radio/X-ray associated objects, totalling 82,344 without any other attribution. The displayed probability is calculated as described in the ARXA/QORG papers.
About 35,000 photometric quasars are radio/X-ray associated, and the displayed probability figure combines the photometric QSO probability P1 and the radio/X-ray derived QSO probability P2 as
P = 1/(1+((1-P1)*(1-P2))/(P1*P2)).Using the probability, as expected, these 1,273,361 objects will yield 1,160,068 actual quasars, making MILLIQUAS a true million-quasar catalog.
The identification of the radio source associated with the quasar candidate, if any.
This is usually the identification of the X-ray source associated with the quasar candidate, if any, but it can also be the identification of a radio lobe, if the radio_name parameter for the object itself contains the name of a radio lobe.
Radio/X-ray detections come from the following catalogs (and their respective home pages):
FIRST: VLA FIRST survey, 13Jun05 version, http://sundog.stsci.edu NVSS: NRAO VLA sky survey, http://www.cv.nrao.edu/nvss SUMSS: Sydney U. Molonglo, http://www.physics.usyd.edu.au/sifa/Main/SUMSS MGPS: Molonglo galactic plane survey, same attribution as SUMSS ROSAT catalogs home page: http://www.mpe.mpg.de/xray/wave/rosat/catalogue -- 1RXH: ROSAT HRI (high resolution imager) -- 1RXS: ROSAT RASS (all-sky survey, both bright & faint) -- 2RXP/2RXF: ROSAT PSPC (position sensitive proportional counter) 1WGA: White, Giommi & Angelini, http://wgacat.gsfc.nasa.gov/wgacat/wgacat.html CXO: Chandra Source Catalog, http://cxc.cfa.harvard.edu/csc CXOX: XAssist Chandra source list, http://xassist.pha.jhu.edu/zope/xassist 3XMM: XMM-Newton, http://xmm.esac.esa.int/xsa XMMSL: XMM-Newton Slew survey, http://www.star.le.ac.uk/~amr30/Slew XMMX: XAssist XMM-Newton source list, http://xassist.pha.jhu.edu/zope/xassist
The identification of the radio lobe or an additional radio or X-ray identification associated with the quasar candidate, if any.
An additional identification of the radio lobe or an extra X-ray identification associated with the quasar candidate, if any.
The HEASARC Browse object classification, based on the information given in the broad_type parameter.