J/ApJ/817/111ivo://CDS.VizieR/J/ApJ/817/111doi:10.26093/cds/vizier.18170111CDSDanforth C.W.Keeney B.A.Tilton E.M.Shull J.M.Stocke J.T.,Stevans M.Pieri M.M.Savage B.D.France K.Syphers D.Smith B.D.,Green J.C.Froning C.Penton S.V.Osterman S.N.2017-10-11T05:13:29Z2016-06-15T07:04:52ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleispectroscopyultraviolet-astronomyredshiftedsurveysWe use high-quality, medium-resolution Hubble Space Telescope/Cosmic Origins Spectrograph (HST/COS) observations of 82 UV-bright active galactic nuclei (AGNs) at redshifts z_AGN_<0.85 to construct the largest survey of the low-redshift intergalactic medium (IGM) to date: 5138 individual extragalactic absorption lines in HI and 25 different metal-ion species grouped into 2611 distinct redshift systems at z_abs_<0.75 covering total redshift pathlengths {Delta}z_HI_=21.7 and {Delta}z_OVI_=14.5. Our semi-automated line-finding and measurement technique renders the catalog as objectively defined as possible. The cumulative column density distribution of HI systems can be parametrized d N(>N)/dz=C_14_(N/10^14^/cm2)^-({beta}-1)^, with C_14_=25+/-1 and {beta}=1.65+/-0.02. This distribution is seen to evolve both in amplitude, C_14_{propto}(1+z)^2.3+/-0.1^, and slope {beta}(z)=1.75-0.31 z for z<=0.47. We observe metal lines in 418 systems, and find that the fraction of IGM absorbers detected in metals is strongly dependent on N_H1_. The distribution of OVI absorbers appears to evolve in the same sense as the Ly{alpha} forest. We calculate contributions to {Omega}_b_ from different components of the low-z IGM and determine the Ly{alpha} decrement as a function of redshift. IGM absorbers are analyzed via a two-point correlation function in velocity space. We find substantial clustering of HI absorbers on scales of {Delta}v=50-300km/s with no significant clustering at {Delta}v>~1000km/s. Splitting the sample into strong and weak absorbers, we see that most of the clustering occurs in strong, N_HI_>~10^13.5^/cm2, metal-bearing IGM systems.2016ApJ...817..111Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/817/111CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/590/A68 : AGN data and absorption-line measurements (Richter+, 2016)J/ApJ/814/40 : Nearby galaxy filaments with UV obs. (Wakker+, 2015)J/MNRAS/449/3263 : Extended galaxy halo gas through HI and OVI (Johnson+, 2015)J/ApJ/759/112 : The UV low-redshift intergalactic medium (Tilton+, 2012)J/ApJ/740/91 : Ly{alpha} & OVI in galaxies around QSOs (Prochaska+, 2011)J/ApJ/736/42 : HST QSO Catalog (Ribaudo+, 2011)J/ApJ/734/65 : CI radial velocities with HST/STIS (Jenkins+, 2011)J/ApJ/710/613 : Broad HI absorbers (Danforth+, 2010)J/ApJ/701/1219 : Galaxy survey in 3 QSO fields (Chen+, 2009)J/ApJS/177/39 : Survey of low-redshift OVI absorbers (Tripp+, 2008)J/ApJ/679/194 : Low-z intergalactic medium. III. (Danforth+, 2008)J/A+A/458/427 : Lyman alpha absorbers in 0.5<z<1.9 QSOs (Janknecht+, 2006)J/MNRAS/335/555 : Lyman-alpha forest of 5 QSOs (Kim+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/817/111https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/817/111http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/817/111https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/817/111https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/817/111http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/817/111GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/817/111/table1 (HST/COS sight lines)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/817/111/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/817/111/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/817/111/table1?GETtext/xml+votable180.050000true0.10175-12.76327780.0055555555555555566/2414 2621 4821 5091 5244 5262 5274 5355 5409 5437 5481 5687 5731 5820 5821 6021 6081 6104 6606 7277 7508 7896 7998 8071 8838 8915 9031 9194 10162 10472 11217 11668 12380 15351 16447 17075 17186 17203 17488 17819 18601 18769 19700 19746 22659 25132 25742 26270 26292 26509 26859 27023 27155 27720 28060 28083 28356 28589 31663 32998 33126 33796 33930 33950 34065 35018 35180 35205 35542 35741 35743 36443 37385 38916 44988 46281 46299 46647 47014 47375https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/817/111?format=asciiUVOpticaldefaultJ/ApJ/817/111/table2COS observation detailsPIPI nameobs.observercharExp130[1/25]? Exposure time for G130M grismkstime.duration;obs.exposurefloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDirNameShort sightline name corresponding to individual subdirectory namesmeta.id;meta.maincharNameName of the sight linemeta.id;spect.linecharDateUT date of the observationtime.epoch;obsnullableS/N130[5/78]? Median S/N per resolution element in the G130M channelstat.snrintnullableExp160[0.5/18]? Exposure time for G160M grismkstime.duration;obs.exposurefloatnullableS/N160[7/47]? Median S/N per resolution element in the G160M channelstat.snrintnullablePID[11484/13008] Program numbermeta.id;obsintJ/ApJ/817/111/linelistHST/COS linelists for all the sightlinesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDirNameShort sightline name corresponding to individual subdirectory namesmeta.id;meta.maincharlambda[1133.4/1797.2] Observed Wavelength in {AA}0.1nmem.wlfloatLineIDLine identifiermeta.id;spect.linecharz[-0.07/0.9] Absorber redshiftsrc.redshiftdoubleSig[0.5/99.9]? Absorber significance level {sigma}stat.fit.goodnessfloatnullableS/N[1/123] S/N per resel.stat.snrfloatEW[0/2814] Equivalent width in m{AA}0.1pmspect.line.eqWidthinte_EW[0/999] Equivalent width uncertainty0.1pmstat.error;spect.line.eqWidthintb[0/150] Doppler b-parameterkm/sspect.dopplerParamfloate_b[0/99.9]? b-parameter uncertaintykm/sstat.errorfloatnullablel_logN[0/1] Limit flag on logN (1=upper limit)meta.code.errorintlogN[0/19.3]? log column densitylog(cm**-2)phys.columnDensityfloatnullablef_logN[i] i=Infmeta.codechare_logN[0/9.99]? log column density uncertaintylog(cm**-2)stat.errorfloatnullablef_e_logN[n] n=NaNmeta.codecharFit[0/1] Line fit quality concerns?meta.codeintLcod[0/9] Line-center optical depth {tau}_0_ (G1)phys.absorption.opticalDepthintISM[0/1] ISM feature?meta.codeintAGN[0/1] AGN-intrinsic feature?meta.codeintJ/ApJ/817/111/systemsHST/COS systems for all the sightlinesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDirNameShort sightline name corresponding to individual subdirectory namesmeta.id;meta.maincharzsys[0.001/0.7] System redshiftsrc.redshift;pos.heliocentricdoubleDelV[12/274] System velocity half-widthkm/sspect.line.widthfloatlambda[1134.9/1793.9] Observed wavelength0.1nmem.wlfloatLineIDLine identifiermeta.id;spect.linecharzabs[0.001/0.7] Line redshiftsrc.redshift;pos.heliocentricdoubleSig[3/99.9] Line Significance Level {sigma}stat.fit.goodnessfloatS/N[1/87] Local S/N per reselstat.snrfloatEW[6/2814] Line equivalent width in m{AA}0.1pmspect.line.eqWidthinte_EW[1/999] Equivalent width uncertainty0.1pmstat.error;spect.line.eqWidthintb[5/150] Line b-valuekm/sspect.dopplerParamfloate_b[1/99.9] b-value uncertaintykm/sstat.errorfloatl_logN[0/1] Limit flag on logN (1=upper limit)meta.code.errorintlogN[11.8/19.3] Line log column densitylog(cm**-2)phys.columnDensity;spect.linefloate_logN[0.01/9.99] Log column density uncertaintylog(cm**-2)stat.errorfloatFit[0/1] Line fit quality concerns?meta.codeintLcod[0/9] Line-center optical depth {tau}_0_ (G1)phys.absorption.opticalDepthintNlsys[1/36] Number of lines in systemmeta.numberintNml[0/22] Number of metal lines in systemmeta.numberintJ/ApJ/817/111/table1HST/COS sight linesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSight line namemeta.id;spect.linecharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainl_zLimit flag on zmeta.code.error;src.redshiftcharz[0.05/0.9] AGN redshiftsrc.redshiftfloatFlux[1/462] Median observed continuum flux in the HST/COS FUV band in units of 10^-15^erg/cm^2^/s/{AA}1e-17W.m**-2.nm**-1phot.flux.density;em.UV.100-200nm;stat.medianfloatTypeAGN typesrc.classcharNlSimbad column added by the CDSmeta.numberintnullableNsSimbad column added by the CDSmeta.numberintnullableNobsSimbad column added by the CDSmeta.numberintnullableSpInteractive plot of spectrummeta.ref.urlcharNEDSimbad column added by the CDSmeta.ref.urlcharDirNameShort sightline name corresponding to individual subdirectory namesmeta.id;meta.mainchar