J/ApJ/640/579ivo://CDS.VizieR/J/ApJ/640/579doi:10.26093/cds/vizier.16400579CDSGlikman E.Helfand D.J.White R.L.2017-07-03T14:26:55Z2008-12-26T23:15:39ZCDS support team

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

cds-question@unistra.frquasarsinfrared-astronomyspectroscopyWe present a near-infrared quasar composite spectrum spanning the wavelength range 0.58-3.5um. The spectrum has been constructed from observations of 27 quasars obtained at the NASA IRTF telescope and satisfying the criteria Ks<14.5 and M_i_<-23; the redshift range is 0.118<z<0.418. The signal-to-noise ratio is moderate, reaching a maximum of 150 between 1.6 and 1.9um. While a power-law fit to the continuum of the composite spectrum requires two breaks, a single power-law slope of alpha=-0.92 plus a 1260K blackbody provides an excellent description of the spectrum from H{alpha} to 3.5um, strongly suggesting the presence of significant quantities of hot dust in this blue-selected quasar sample. We measure intensities and line widths for 10 lines, finding that the Paschen line ratios rule out case B recombination. We compute K-corrections for the J, H, K, and Spitzer 3.6um bands, which will be useful in analyzing observations of quasars up to z=10.2006ApJ...640..579Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/640/579CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/252 : SDSS-DR5 quasar catalog (Schneider+, 2007)http://www.sdss.org : SDSS Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/640/579https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/640/579http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/640/579https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/640/579https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/640/579http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/640/579GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/640/579/list (List of studied QSOs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/640/579/list?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/640/579/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/640/579/list?GETtext/xml+votable180.050000true2.4295833-9.14422220.0055555555555555566/6391 8197 9948 10217 10234 17260 17321 17499 17560 17665 17819 17822 17834 18020 18093 18769 18771 19740 19741 23048 23216 26223 26225 36719 36788 49014 49019https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/640/579?format=asciiInfrareddefaultJ/ApJ/640/579/listList of studied QSOsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainFileNameName of the spectra file in sp subdirectorymeta.id;meta.filecharSloanDisplay the SDSS data for this quasarmeta.ref.urlcharJ/ApJ/640/579/table8Quasar K-correctionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintzRedshiftsrc.redshiftfloatKc(J)? 2MASS J band K-correctionmagarith.factor;phot.magfloatnullableKc(H)? 2MASS H band K-correctionmagarith.factor;phot.magfloatnullableKc(K)? 2MASS K_S_ band K-correctionmagarith.factor;phot.magfloatnullableKc(3.6)Spitzer IRAC 3.6 micron band K-correctionmagarith.factor;phot.magfloatJ/ApJ/640/579/table7Optical-to-infrared composite quasar spectrum, arithmetic and geometric meansrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLambdaWavelength in Angstroms0.1nmem.wlfloatFluxArithmetic mean flux in arbitrary unitsphot.flux.density;em.IRfloate_FluxError in Fluxstat.error;phot.fluxfloatGFluxGeometric mean flux in arbitrary unitsphot.flux.density;em.IRfloatJ/ApJ/640/579/table3Composite quasar spectrum, arithmetic and geometric meansrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLambdaWavelength in Angstroms0.1nmem.wlfloatFluxArithmetic mean flux in arbitrary unitsphot.flux.density;em.IRfloate_FluxError in Fluxstat.error;phot.fluxfloatGFluxGeometric mean flux in arbitrary unitsphot.flux.density;em.IRfloat