J/A+A/619/A95ivo://CDS.VizieR/J/A+A/619/A95doi:10.26093/cds/vizier.36190095CDSChiaraluce E.Vagnetti F.Tombesi F.Paolillo M.2020-05-04T10:53:24Z2018-11-12T09:06:44ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiquasarsx-ray-sourcesultraviolet-astronomyThe well established negative correlation between the {alpha}_OX_ spectral slope and the optical/UV luminosity, a by product of the relation between X-rays and optical/UV luminosity, is affected by a relatively large dispersion. The main contributions can be variability in the X-ray/UV ratio and/or changes in fundamental physical parameters. We want to quantify the contribution of variability within single sources (intra-source dispersion) and that due to variations of other quantities different from source to source (inter-source dispersion). We use archival data from the XMM-Newton Serendipitous Source Catalog (XMMSSC, Cat. IX/50) and from the XMM-OM Serendipitous Ultra-violet Source Survey (XMMOM-SUSS3, Cat. II/340). We select a sub-sample in order to decrease the dispersion of the relation due to the presence of Radio-Loud and Broad Absorption Line objects, and to absorptions in both X-ray and optical/UV bands. We use the Structure Function (SF) to estimate the contribution of variability to the dispersion. We analyse the dependence of the residuals of the relation on various physical parameters in order to characterise the inter-source dispersion. We find a total dispersion of {sigma}~0.12 and we find that intrinsic variability contributes for 56 percent of the variance of the {alpha}_OX_-L_UV_ relation. If we select only sources with a larger number of observational epochs (>2) the dispersion of the relation decreases by approximately 15 percent. We find weak but significant dependences of the residuals of the relation on black-hole mass and on Eddington ratio, which are also confirmed by a multivariate regression analysis of {alpha}_OX_ as a function of UV luminosity and black-hole mass and/or Eddington ratio. We find a weak positive correlation of both the {alpha}_OX_ index and the residuals of the {alpha}_OX_-LUV relation with inclination indicators, such as the FWHM(H{beta}) and the EW[OIII], suggesting a weak increase of X-ray/UV ratio with the viewing angle. This suggests the development of new viewing angle indicators possibly applicable at higher redshifts. Moreover, our results suggest the possibility of selecting a sample of objects, based on their viewing angle and/or black-hole mass and Eddington ratio, for which the {alpha}_OX_-LUV relation is as tight as possible, in light of the use of the optical/UV-X-ray luminosity relation to build a distance modulus (DM)-z plane and estimate cosmological parameters.2018A&A...619A..95Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/619/A95CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/340 : XMM-OM Serendipitous Source Survey Catalogue, XMM-SUSS2.1IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5IX/50 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR6VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/A+A/593/A55 : MEXSAS catalogue (Vagnetti+, 2016)J/ApJS/228/9 : Physical parameters of ~300000 SDSS-DR12 QSOs (Kozlowski, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/619/A95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/619/A95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/619/A95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/619/A95https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/619/A95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/619/A95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/619/A95/table2 (The Reference sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/619/A95/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/619/A95/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/619/A95/table2?GETtext/xml+votable180.050000true24.97096.34950.0055555555555555565/4422-4423 6814 6/4206 4352 4438-4439 4536 4653 4804 4964 5069 5074 5109 5130 5367 5420 5469 5560 5569 5576 5857 5860 5862 5939 5945 5970 5984 6020-6021 6035 6040 6047 6069 6073 6077 6098 6112 6251 6337 6495 6539 6977 7178 7266 7281 7308-7309 7311 7349 7409 7426 8195-8196 8220 8324 8339 8675 8707 8809 8909 8922 8927 8952 9036 9077 9168 9192 9231 9287 9343 9347 9354 9401 9465 9468 9476-9477 9512 9612 9752 9831 9959 9997 10183 10189-10191 10213-10214 10265 10293 10306 10348 10378 10400-10401 10413 10484 10549 10598 10601 10604-10605 10645 10769 10856 10888 10905 10912 10979-10980 10982 10989 11027 11048 11050 11101 11127 11185 11204 11206 11252 11375 11382 11416 11424 11436 11463 11591 11596 11779 11810 11829 11936 17497 17622 17671 17677 17679 17682-17683 17697 17712-17713 17715-17716 17752 17754-17755 17767 17772 18207 18258 18773 19033 19036 19402 19978 23209 25944 25966 25968 25972 25982 25989 25991 26022 26080 26082 26189 26292 26300 26561 26563 27005 27081 27124 27127 27223 27225 27245-27247 27307 27428 27580 27719 27730 27742 27765 27767 27773 27860 27862 27907 27913 27941 27950 28026 28045 28127 28221 28226 28234 28251 28275 28278 28284 28344 28351 28356 28430 28452 28497 28517 28535 28541 28555 28583 28632 28636-28637 31397 31712 32418 32486 32500 36765 36774 36785https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/619/A95?format=asciiX-rayUVdefaultJ/A+A/619/A95/table2The Reference samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMEXSAS2Source number in the MEXSAS2 cataloguemeta.idintNameSDSS source name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension of the SDSS identification (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of the SDSS identification (J2000)degpos.eq.dec;meta.mainzRedshiftsrc.redshiftfloatlogMBH? log black hole masslog(solMass)phys.massfloatnullablelogLbol? log bolometric luminositylog(1e-07W)phys.luminosityfloatnullablelogL/LEdd? log Eddington ratiophys.luminosity;arith.ratiofloatnullableNepoNumber of observing epochsmeta.numberintTimeTime of observation (MJD)dtime.epochfloatlogLUVlog monochromatic luminosity at 2500{AA}log(1e-07W.Hz**-1)phys.luminosity;em.UVfloate_logLUVError log monochromatic luminosity at 2500{AA}log(1e-07W.Hz**-1)stat.errorfloatlogLXlog monochromatic luminosity at 2keVlog(1e-07W.Hz**-1)phys.luminosity;em.X-ray.softfloate_logLXError log monochromatic luminosity at 2keVlog(1e-07W.Hz**-1)stat.errorfloataoxX-ray-to-optical indexphys.luminosity;arith.ratiofloate_aoxError X-ray-to-optical indexstat.errorfloatSloanDisplay the online SDSS data for this sourcemeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar