J/ApJ/805/122ivo://CDS.VizieR/J/ApJ/805/122doi:10.26093/cds/vizier.18050122CDSLuo B.Brandt W.N.Hall P.B.Wu J.Anderson S.F.Garmire G.P.,Gibson R.R.Plotkin R.M.Richards G.T.Schneider D.P.Shemmer O.,Shen Y.2017-10-16T14:57:39Z2015-10-19T14:58:48ZCDS support team

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

cds-question@unistra.frx-ray-sourcesquasarsredshiftedWe present an X-ray and multiwavelength study of 33 weak emission-line quasars (WLQs) and 18 quasars that are analogs of the extreme WLQ, PHL1811, at z~0.5-2.9. New Chandra 1.5-9.5ks exploratory observations were obtained for 32 objects while the others have archival X-ray observations. Significant fractions of these luminous type 1 quasars are distinctly X-ray weak compared to typical quasars, including 16 (48%) of the WLQs and 17 (94%) of the PHL 1811 analogs with average X-ray weakness factors of 17 and 39, respectively. We measure a relatively hard ({Gamma}=1.16^+0.37^_-0.32_) effective power-law photon index for a stack of the X-ray weak subsample, suggesting X-ray absorption, and spectral analysis of one PHL 1811 analog, J1521+5202, also indicates significant intrinsic X-ray absorption. We compare composite Sloan Digital Sky Survey spectra for the X-ray weak and X-ray normal populations and find several optical-UV tracers of X-ray weakness, e.g., FeII rest-frame equivalent width (REW) and relative color. We describe how orientation effects under our previously proposed "shielding-gas" scenario can likely unify the X-ray weak and X-ray normal populations. We suggest that the shielding gas may naturally be understood as a geometrically thick inner accretion disk that shields the broad line region from the ionizing continuum. If WLQs and PHL 1811 analogs have very high Eddington ratios, the inner disk could be significantly puffed up (e.g., a slim disk). Shielding of the broad emission-line region by a geometrically thick disk may have a significant role in setting the broad distributions of CIV REW and blueshift for quasars more generally.2015ApJ...805..122Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/805/122CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015)VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/AJ/149/203 : Reddening of ~35000 quasars from SDSS (Krawczyk+, 2015)J/A+A/570/A96 : GTC spectra of z~2.3 quasars (Sulentic+, 2014)J/A+A/568/A114 : SDSS quasars with weak emission lines (Meusinger+, 2014)J/ApJS/213/26 : Optical light curves of PHL1811 and 3C273 (Fan+, 2014)J/ApJS/206/4 : SED & bolometric corrections for QSOs (Krawczyk+, 2013)J/ApJ/757/51 : FIRST-2MASS dust-reddened QSO spectra (Glikman+, 2012)J/ApJ/756/52 : R-band light curve of QSO J0158-4325 images (Morgan+, 2012)J/ApJ/747/10 : X-ray and multiwavelength properties of 11 WLQs (Wu+, 2012)J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012)J/ApJ/746/54 : Chandra X-ray observations of SDSS-DR5 QSOs (Gibson+, 2012)J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJS/194/42 : SDSS-DR3 MgII-based black hole masses (Rafiee+, 2011)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/A+A/512/A34 : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)J/AJ/139/390 : Optically selected BL Lac objects from SDSS (Plotkin+, 2010)J/ApJ/699/782 : High-redshift SDSS-DR5 QSOs (Diamond-Stanic+, 2009)J/ApJ/696/580 : Properties of weak emission-line QSOs (WLQ) (Shemmer+, 2009)J/ApJ/685/773 : X-ray-UV relations in SDSS DR5 QSOs (Gibson+, 2008)J/AJ/135/2453 : Sample of BL Lac objects from SDSS and FIRST (Plotkin+, 2008)J/ApJS/169/353 : Chandra sources in M17 (Broos+, 2007)J/ApJS/166/470 : SDSS-Spitzer type I QSOs IR photometry (Richards+, 2006)J/AJ/129/2542 : BL Lac from SDSS (Collinge+, 2005)J/AJ/122/503 : SDSS u*g*r*i*z* phot. and redshift of QSOs (Anderson+, 2001)J/AJ/121/2308 : Sloan Digital Sky Survey quasar photometry (Richards+, 2001)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/805/122https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/805/122http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/805/122https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/805/122https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/805/122http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/805/122GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/805/122/table5 (Bolometric luminosity, supermassive black hole (SMBH) mass, and Eddington ratio estimates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/805/122/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/805/122/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/805/122/table5?GETtext/xml+votable180.050000true26.88993440.05645610.0055555555555555566/4150 4279 4352 4401 4604 4613 4962 5305 5847 5956 7173 7318 7330 8674 8698 8741 8934 9264 9787 9842 9988 10122 10202 10424 10570 10574 11034 11117 11120 11332 11339 11790 17829 18582 19110 19663 19993 21969 25936 26102 26956 26981 27774 27833 28062 28148 28244 28533 35258 47011 49011https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/805/122?format=asciiX-rayOpticaldefaultJ/ApJ/805/122/table5Bolometric luminosity, supermassive black hole (SMBH) mass, and Eddington ratio estimatesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceObservation or archive (1)meta.bibcharsetObject type (p=PHL1811 analogs; w=weak-line quasars)src.classcharNameObject identifier (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharlogL[45.3/48.2] Log bolometric luminosity; erg/slog(1e-07W)phys.luminosityfloatlogM[-1/10]? Log black hole mass (2)log(solMass)phys.massfloatnullablef_logM[-1/2] Flag on logM (3)meta.codeintLEdd[-1/2.9]? Eddington ratio estimate (2)phys.luminosity;arith.ratiofloatnullableQCatSources within 1" from the Veron+, 2010, VII/258 and Schneider+, 2010 catalogsmeta.ref.urlintnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharNEDSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/805/122/table1New Chandra observations and X-ray photometric propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSetObject type (p=PHL1811 analogs; w=weak-line quasars (WLQs))src.classcharNameObject name (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharf_Namea: included in this table but not in figures or our analyses (see section 2.2)meta.codecharz[0.4/3] Redshiftsrc.redshiftfloatobsIDChandra observation ID numbermeta.id;obsintDateObservation start datetime.start;obsnullableExp[1.5/37.1] Background-flare cleaned effective exposure time in the 0.5-8keV bandkstime.duration;obs.exposure;em.X-ray.mediumfloatl_SctsLimit flag on Scts (1)meta.code.errorcharScts[2/51.2] Aperture-corrected source counts in the soft (0.5-2keV) bandctphot.count;em.X-rayfloate_Scts[1.3/7.3]? Negative error on Sctsctstat.errorfloatnullableE_Scts[2.7/8.4]? Positive error on Sctsctstat.error;stat.maxfloatnullablel_HctsLimit flag on Hcts (1)meta.code.errorcharHcts[2.1/47.9] Aperture-corrected source counts in the hard (2-8keV) bandctphot.count;em.X-rayfloate_Hcts[1.4/7.3]? Negative error on Hctsctstat.errorfloatnullableE_Hcts[2.9/8.5]? Positive error on Hctsctstat.error;stat.maxfloatnullablel_HRLimit flag on HRmeta.code.errorcharHR[0.1/3.2]? Ratio between the soft-band and hard-band counts (2)meta.notefloatnullablee_HR[0.07/2.3]? Negative error on HRstat.errorfloatnullableE_HR[0.1/6.2]? Positive error on HRstat.error;stat.maxfloatnullablel_GamLimit flag on Gammeta.code.errorcharGam[-0.3/2.2]? 0.5-8keV effective power-law photon index (3)meta.code;spect.index;em.X-ray.mediumfloatnullablee_Gam[0.2/0.9]? Negative error on Gamstat.errorfloatnullableE_Gam[0.2/1.3]? Positive error on Gamstat.error;stat.maxfloatnullableCommComment (W11=Wu et al., 2011ApJ...736...28W)meta.notechar