J/A+A/564/A117ivo://CDS.VizieR/J/A+A/564/A117doi:10.26093/cds/vizier.35640117CDSGattano C.Souchay J.Barache C.2014-08-06T10:23:07Z2014-07-23T13:34:40ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frquasarsredshiftedphotometryThanks to huge surveys, such as the Sloan Digital Sky Survey (SDSS), the last decade has shown a dramatic increase in the number of known quasars. In the second release of the general compiled catalogue Large Quasar Astrometric Catalogue (LQAC), 187504 objects are recorded. From this catalogue, we carry out statistical studies dealing with several topics: the astrometric accuracy of the quasars, their spatial location, the distribution of the distance to the closest neighbour, the identification of binary quasars, the completness of catalogues at a given magnitude and the estimation of the number of quasars expected to be detected by the astrometric space mission Gaia. We analyse the astrometric improvements brought by the LQAC-2 in terms of equatorial coordinates off-sets. We plot the bi-dimensional spatial distribution of the LQAC-2 quasars according to their equatorial, galactic, and ecliptic coordinates, thus exploring the anisotropy of the distribution. We compare the observed distribution of closest neighbours with the theoretical values based on a Poisson distribution. Moreover, we perform a comparison between two catalogues, the SDSS and the 2dF inside a huge common field. By extrapolating to the whole sky we deduce the number of quasars that will be detected by Gaia.2014A&A...564A.117Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/564/A117CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/158 : Revised and Updated Catalog of QSO (Hewitt+ 1993)VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)J/A+A/494/799 : Large Quasar Astrometric Catalogue (LQAC) (Souchay+, 2009)J/A+A/537/A99 : Large Quasar Astrometric Catalogue 2 (LQAC-2) (Souchay+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/564/A117https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/564/A117http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/564/A117https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/564/A117https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/564/A117http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/564/A117GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/564/A117/tab3-6 (Binary quasars (tables 3-6))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/564/A117/tab3-6?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/564/A117/tab3-6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/564/A117/tab3-6?GETtext/xml+votable180.050000true169.0266713.968901940.005555555555555556Cone search capability for table J/A+A/564/A117/table7 (Binary quasars with the shortest separation, between 0" and 30")https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/564/A117/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/564/A117/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/564/A117/table7?GETtext/xml+votable180.050000true250.7972631.938443890.0055555555555555566/0 2207 4262 4274 4819 4952 5008 5103 5332 5359 5372 5582 5643 5664 5733 5757 5824 5843 5851 5870 5874 5925 6402 6462 6495 6578 7225 7259 7424 7468 7525 7606 8352 8452 8526 8552 8799 8845 8939 8988 9058 9268 9272 9281 9327 9357 9359 9415 9458 9481 9632-9633 9642 9927 9950 10213 10292-10293 10312 10336 10379 10394 10396 10404 10418 10433 10555 10634 10743 10925 10977 10995 11017 11029 11064 11188 11228 11300 11341 11384 11456 11955 12317 12531 12639 17577 17746 17749 17820 18025 18070 18092 18777 18780 18841 18860 18880 19052 19093 19325 19424 19426 19466 19618 21968 23193 25934 26021 26024-26025 26032 26050 26196 26204 26220 26396 26485 26531 26555 26962 26964 27021 27031 27091 27257 27259 27305 27307 27434 27544 27648 27717 27765 27787 27790 27852 27865 28175 28184 28371 28478 28519 31449 32497 32527 36725 49015https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/564/A117?format=asciiOpticaldefaultJ/A+A/564/A117/tab3-6Binary quasars (tables 3-6)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintT[3/6] Table number (1)meta.id;meta.mainintQSO1/2Quasar names (NNN+NNN_NNN/NNN)meta.id;meta.maincharNPresence of this binary quasar in the different tablesmeta.ref.urlintnullablez1Redshift of first quasarsrc.redshiftfloatz2Redshift of second quasarsrc.redshiftfloattheta[2/22] Separation anglearcsecposfloatU1mag? U magnitude of first quasarmagphot.mag;em.opt.UfloatnullableU2mag? U magnitude of first quasarmagphot.mag;em.opt.UfloatnullableRefReference (2)meta.ref;pos.framecharMult[*+] Indicates the other quasar for the tripletmeta.codecharQSO1First QSO name (NNN+NNN_NNN)meta.idcharQSO2Second QSO name (NNN+NNN_NNN)meta.idcharLQAC-2Display the LQAC-2 data (Souchay et al. 2012, J/A+A/537/A99)meta.ref.urlchar_RAPosition of first QSO from LQAC-2 (Cat. J/A+A/537/A99) (right ascension part)degpos.eq.ra;meta.main_DEPosition of first QSO from LQAC-2 (Cat. J/A+A/537/A99) (declination part)degpos.eq.dec;meta.mainJ/A+A/564/A117/table7Binary quasars with the shortest separation, between 0" and 30"recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSO1/2Quasar names (NNN+NNN_NNN/NNN)meta.id;meta.maincharprimaryNPresence of this binary quasar in the different tablesmeta.ref.urlintnullableU1mag? U magnitude of first quasarmagphot.mag;em.opt.UfloatnullableU2mag? U magnitude of first quasarmagphot.mag;em.opt.Ufloatnullabletheta[2/30] Separation anglearcsecposfloatz1Redshift of first quasarsrc.redshiftfloatz2Redshift of second quasarsrc.redshiftfloatRef1[A-M -] Reference (1)meta.ref;pos.framecharRef2[A-M -] Reference (1)meta.ref;pos.framecharSeqU[1/160] Sequential number in terms of increasing magnitude U of the brightest componentmeta.idintSeqz[1/160] Sequential number in terms of decreasing value of zmeta.idintQSO1First QSO name (NNN+NNN_NNN)meta.idcharQSO2Second QSO name (NNN+NNN_NNN)meta.idcharLQAC-2Display the LQAC-2 data (Souchay et al. 2012, J/A+A/537/A99)meta.ref.urlchar_RAPosition of first QSO from LQAC-2 (Cat. J/A+A/537/A99) (right ascension part)degpos.eq.ra;meta.main_DEPosition of first QSO from LQAC-2 (Cat. J/A+A/537/A99) (declination part)degpos.eq.dec;meta.main