J/A+A/617/A118ivo://CDS.VizieR/J/A+A/617/A118doi:10.26093/cds/vizier.36170118CDSSaturni F.G.Bischetti M.Piconcelli E.Bongiorno A.Cicone C.,Feruglio C.Fiore F.Gallerani S.Giustini M.Piranomonte S.,Vietri G.Vignali C.2018-10-01T13:20:01Z2018-09-26T08:06:27ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiquasarsspectroscopyWe present the analysis of the rest-frame optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at z=3.911. The spectroscopic data are taken with the optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between CIII] {lambda}1910 and [OIII] {lambda}{lambda}4959,5007. We investigate the possible presence of multiple BALs by computing "balnicity" and absorption indexes (i.e. BI, BI_0_ and AI) for the transitions SiIV {lambda}1400, CIV {lambda}1549, AlIII {lambda}1860 and MgII {lambda}2800. No clear evidence for the presence of absorption features is found in addition to the already known, prominent BAL associated to C IV, which supports a high-ionization BAL classification for APM 08279+5255. We also study the properties of the [OIII], H{beta} and MgII emission lines. We find that [OIII] is intrinsically weak (F_[OIII]_/F_H{beta}_<~0.04), as it is typically found in luminous quasars with a strongly blueshifted CIV emission line (2500km/s for APM 08279+5255). We compute the single-epoch black hole mass based on MgII and H{beta} broad emission lines, finding M_BH_=(2/3)*10^10^{mu}^-1^M_{sun}_, with the magnification factor {mu} that can vary between 4 and 100 according to CO and rest-frame UV-to-mid-IR imaging respectively. Using a MgII equivalent width (EW)-to-Eddington ratio relation, the EW_MgII_~27{AA} measured for APM 08279+5255 translates into an Eddington ratio of ~0.4, which is more consistent with {mu}=4. This magnification factor also provides a value of M_BH_ that is consistent with recent reverberation-mapping measurements derived from CIV and SiIV.2018A&A...617A.118Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/617/A118CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/608/A30 : APM 08279+5255 CO(4-3) spectrum (Feruglio+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/617/A118https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/617/A118http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/617/A118https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/617/A118https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/617/A118http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/617/A118GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/617/A118/apm08279APM 08279+5255 calibrated spectrum before dereddening with corresponding 1{sigma} uncertaintiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLambdaObserver-frame wavelength0.1nmem.wldoubleFluxObserver-frame specific flux (erg/cm^2^/s/{AA})10mW.m**-2.nm**-1phot.fluxdoublee_FluxObserver-frame flux uncertainty (erg/cm^2^/s/{AA})10mW.m**-2.nm**-1stat.error;phot.fluxdouble