J/ApJ/747/10ivo://CDS.VizieR/J/ApJ/747/10doi:10.26093/cds/vizier.17470010CDSWu J.Brandt W.N.Anderson S.F.Diamond-Stanic A.M.Hall P.B.,Plotkin R.M.Schneider D.P.Shemmer O.2017-06-13T11:09:05Z2013-10-24T09:00:36ZCDS support team

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

cds-question@unistra.frquasarsredshiftedbl-lacertae-objectsx-ray-sourcesultraviolet-astronomyline-intensitiesWe report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z=0.4-2.5. Our sample was selected from the Plotkin et al. catalog (2010, Cat. J/AJ/139/390) of radio-quiet, weak-featured active galactic nuclei (AGNs). The distribution of relative X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is significantly different from that of typical radio-quiet quasars, having an excess of X-ray weak sources, but it is consistent with that of high-redshift WLQs. Over half of the low-redshift WLQ candidates are X-ray weak by a factor of >~5, compared to a typical SDSS quasar with similar UV/optical luminosity. These X-ray weak sources generally show similar UV emission-line properties to those of the X-ray weak quasar PHL 1811 (weak and blueshifted high-ionization lines, weak semiforbidden lines, and strong UV Fe emission); they may belong to the notable class of PHL 1811 analogs. The average X-ray spectrum of these sources is somewhat harder than that of typical radio-quiet quasars.2012ApJ...747...10Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/747/10CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2013)B/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)J/ApJS/206/4 : SED for luminous QSOs (Krawczyk+, 2013)J/ApJ/746/54 : Chandra X-ray observations of SDSS-DR5 QSOs (Gibson+, 2012)J/ApJ/726/20 : X-ray emission from quasars (Miller+, 2011)J/AJ/139/390 : SDSS-DR7 optically selected BL Lac objects (Plotkin+, 2010)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/ApJ/702/767 : CIV and FeK{alpha} Baldwin effects in AGNs (Wu+, 2009)J/ApJ/696/580 : Properties of weak emission-line QSOs (WLQ) (Shemmer+, 2009)J/ApJ/699/782 : High-redshift SDSS-DR5 QSOs (Diamond-Stanic+, 2009)J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)J/ApJS/183/17 : The SDSS DR5/XMM-Newton quasar survey (Young+, 2009)J/A+A/434/475 : Redshifts for X-ray selected AGNs (Kitsionas+, 2005)J/AJ/129/2542 : BL Lac from SDSS (Collinge+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/747/10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/747/10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/747/10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/747/10https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/747/10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/747/10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/747/10/wlqs (Weak-line quasar candidate properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/747/10/wlqs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/747/10/wlqs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/747/10/wlqs?GETtext/xml+votable180.050000true123.21162552.42522220.0055555555555555566/4352 5432 5847 7330 8674 9842 10122 18601 19110 19993 26956 28148https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/747/10?format=asciiX-rayUVOpticaldefaultJ/ApJ/747/10/wlqsWeak-line quasar candidate propertiesl_FctLimit flag on Fbandmeta.code.errorcharnullableE_Sct[3/21.2]? Positive error on Sct (5)ctstat.error;stat.maxfloatnullableMJD[52051/55702]? Modified Julian daydtime.epochintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSet[A/C] C=Chandra cycle 12 objects; A=archival X-ray data objectsmeta.bibcharSDSSSDSS name (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharnullablez[0.39/2.5] Redshift for each source (1)src.redshiftfloatnullabledOX[0/1]? Angular distance between the optical and X-ray positions; no entry=no X-ray detectionarcsecpos.angDistancefloatnullableDetDetector (ACIS-I, -S or MOS)meta.idcharnullablef_Det[c] More than one detector (2)meta.codecharnullableDateObservation datetime.epoch;obsnullableObsIDObservation numbermeta.idnullableExp[3/27] Exposure timekstime.duration;obs.exposurefloatnullableOA[0.3/6.4] Off-axis anglearcmininstr.offsetfloatnullableRef[,1-4] Reference(s) number (3)meta.idcharnullableDR9Cross-match within 2" with the SDSS-DR9 photometric catalogmeta.ref.urlintnullableRef1Origin of spectroscopic data (4)meta.ref;pos.framechars(CIV)[-7300/-570]? CIV blueshiftkm/sspect.dopplerVelocintnullablee_s(CIV)[30/1700]? s(CIV) uncertaintykm/sstat.errorintnullablel_W(CIV)Limit flag on W(CIV)meta.code.errorcharW(CIV)[3/30]? CIV rest equivalent width0.1nmspect.line.eqWidthfloatnullablee_W(CIV)[0.3/2.7]? W(CIV) uncertainty0.1nmstat.errorfloatnullablel_W(SiIV)Limit flag on W(SiIV)meta.code.errorcharW(SiIV)[4.8/9.9]? SiIV rest equivalent width (5)0.1nmspect.line.eqWidthfloatnullablee_W(SiIV)[0.3/2.1]? W(SiIV) uncertainty (5)0.1nmstat.errorfloatnullablel_W(190)Limit flag on W(190)meta.code.errorcharW(190)[1.9/21.7]? 1900{AA} rest equivalent width (6)0.1nmspect.line.eqWidthfloatnullablee_W(190)[0.2/2.1]? W(190) uncertainty (6)0.1nmstat.errorfloatnullablel_W(FeIII)Limit flag on W(FEIII)meta.code.errorcharW(FeIII)[1.7/9]? FeIII rest equivalent width0.1nmspect.line.eqWidthfloatnullablee_W(FeIII)[0.1/1.5]? W(FeIII) uncertainty0.1nmstat.errorfloatnullableW(MgII)[5.8/17.1]? MgII rest equivalent width0.1nmspect.line.eqWidthfloatnullablee_W(MgII)[0.4/1.1]? W(MgII) uncertainty0.1nmstat.errorfloatnullableSimbadSimbad column added by the CDSmeta.refcharNEDSimbad column added by the CDSmeta.refcharFct[3.3/552.3] Full band (0.5-8keV) X-ray countsctphot.count;em.X-rayfloatnullableE_Fct[3/24.5]? Positive error on Fct (5)ctstat.error;stat.maxfloatnullablee_Fct[1.7/23.5]? Negative error on Fct (5)ctstat.errorfloatnullablel_SctLimit flag on Sctmeta.code.errorcharnullableSct[3.1/406.4] Soft band (0.5-2keV) X-ray countsctphot.count;em.X-rayfloatnullablee_Sct[1.7/20.2]? Negative error on Sct (5)ctstat.errorfloatnullablel_HctLimit flag on Hctmeta.code.errorcharnullableHct[2.1/145.8] Hard band (2-8keV) X-ray countsctphot.count;em.X-rayfloatnullableE_Hct[2.7/13.1]? Positive error on Hct (5)ctstat.error;stat.maxfloatnullablee_Hct[1.3/12.1]? Negative error on Hct (5)ctstat.errorfloatnullablel_H/SLimit flag on H/Smeta.code.errorcharnullableH/S[0.2/2.25]? Band ratio (6)phot.count;arith.ratiofloatnullableE_H/S[0.04/0.81]? Positive error on H/S (6)stat.error;stat.maxfloatnullablee_H/S[0.03/0.4]? Negative error on H/S (6)stat.errorfloatnullablel_GammaLimit flag on Gammameta.code.errorcharnullableGamma[-0.01/2.21]? Effective power-law photon index {Gamma} (7)meta.code;spect.indexfloatnullableE_Gamma[0.09/1.31]? Positive error on Gammastat.error;stat.maxfloatnullablee_Gamma[0.09/0.87]? Negative error on Gammastat.errorfloatnullable_RAPositions from SDSS names (right ascension part)degpos.eq.ra;meta.mainnullable_DEPositions from SDSS names (declination part)degpos.eq.dec;meta.mainnullableJ/ApJ/747/10/table3Continuum S/N values for SDSS DR7 quasarsNp170Number of pixels at 1650-1750 A (4)meta.numberintFiberFiber numbermeta.idintSN170[0/85]? Signal-to-noise ratio at 1650-1750A (3)stat.snrfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS name (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharimag[0/22.36] The apparent i-band magnitude (1)magphot.mag;em.opt.Ifloatz[0.06/5.47] Redshift (2)src.redshiftfloatMJDModified Julian Daydtime.epochintPlatePlate numbermeta.id;instr.plateint1700l? Wavelength lower limit; in Angstroms (5)0.1nmem.wlintnullable1700u[3788/9256]? Wavelength upper limit; in {AA} (6)0.1nmem.wlintnullableSN300[0/77]? Signal-to-noise ratio at 2950-3050A (3)stat.snrfloatnullableNp300Number of pixels at 2950-3050 A (4)meta.numberint3000l? Wavelength lower limit; in Angstroms (5)0.1nmem.wlintnullable3000u[3796/9270]? Wavelength upper limit; in {AA} (6)0.1nmem.wlintnullableSN515[0/82]? Signal-to-noise ratio at 5100-5200 A (3)stat.snrfloatnullableNp515Number of pixels at 2950-3050 A (4)meta.numberint5150l? Wavelength lower limit; in Angstroms (5)0.1nmem.wlintnullable5150u[5535/9273]? Wavelength upper limit; in {AA} (6)0.1nmem.wlintnullableSloanDisplay the online SDSS data for this quasarmeta.ref.urlchar