J/A+A/590/A68ivo://CDS.VizieR/J/A+A/590/A68doi:10.26093/cds/vizier.35900068CDSRichter P.Wakker B.P.Fechner C.Herenz P.Tepper-Garcia T.Fox A.J.2018-05-02T07:51:05Z2016-05-12T07:49:05ZCDS support team

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

cds-question@unistra.frquasarsastrometryredshiftedspectroscopyline-intensitiesDoubly ionized silicon (SiIII) is a powerful tracer of diffuse ionized gas inside and outside of galaxies.It can be observed in the local Universe in ultraviolet (UV) absorption against bright extragalactic background sources. We here present an extensive study of intervening SiIII-selected absorbers and study the properties of the warm circumgalactic medium (CGM) around low-redshift (z<0.1) galaxies. We analyzed the UV absorption spectra of 303 extragalactic background sources, as obtained with the Cosmic Origins Spectrograph (COS) on-board the Hubble Space Telescope (HST). We developed a geometrical model for the absorption-cross section of the CGM around the local galaxy population and compared the observed SiIII absorption statistics with predictions provided by the model. We also compared redshifts and positions of the absorbers with those of ~64,000 galaxies using archival galaxy-survey data to investigate the relation between intervening SiIII absorbers and the CGM. Along a total redshift path of {Delta}z~24, we identify 69 intervening SiIII systems that all show associated absorption from other low and high ions (e.g., HI, SiII, SiIV, CII, CIV). We derive a bias-corrected number density of dN/dz(SiIII)=2.5+/-0.4 for absorbers with column densities log N(SiIII)>12.2, which is ~3 times the number density of strong MgII systems at z=0. This number density matches the expected cross section of a SiIII absorbing CGM around the local galaxy population with a mean covering fraction of <f_c_>=0.69. For the majority (~60 percent) of the absorbers, we identify possible host galaxies within 300km/s of the absorbers and derive impact parameters {rho}<200kpc, demonstrating that the spatial distributions of SiIII absorbers and galaxies are highly correlated. Our study indicates that the majority of SiIII-selected absorbers in our sample trace the CGM of nearby galaxies within their virial radii at a typical covering fraction of ~70 percent. We estimate that diffuse gas in the CGM around galaxies, as traced by SiIII contains substantially more (more than twice as much) baryonic mass than their neutral interstellar medium.2016A&A...590A..68Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/590/A68CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/590/A68https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/590/A68http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/590/A68https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/590/A68https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/590/A68http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/590/A68GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/590/A68/tablea1 (QSO names, coordinates, and emission redshifts)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/590/A68/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/590/A68/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/590/A68/tablea1?GETtext/xml+votable180.050000true157.8350.890.0055555555555555566/0 134 552 2414 2621 2663 2754 4107 4193 4256 4410 4590 4821 4824 4946 4959 4961 4966 5026 5061 5091 5121 5215 5244 5262 5274 5284 5304-5305 5351 5409 5413 5423 5437 5481 5529 5570 5639 5657 5687 5731 5759 5773 5814 5820-5821 5861 5974 5995 6021 6081 6087 6098 6104 6223 6488 6606 7259 7272 7277 7281 7381 7460 7508 7642 7763 7902-7903 7998 8071 8245-8246 8266 8282 8303 8328 8469 8528 8700 8702 8716 8755 8838 8867 8915 8918 8922 8927 8938-8939 8952 9018 9031 9111 9175 9186 9305 9440 9457 9753 9756 9783 9817 10144 10162 10170 10192 10261 10287 10297 10300 10393 10433 10472 10517 10528 10602 10634 10659 10689 10764 10889 10927 10940 10969 11009 11021 11206 11209 11217 11327 11354 11382 11388 11396 11435 11456 11462 11475 11490 11557 11610 11658 11668 11686 11898 12033 12047 12380 13414 15247 15351 16712 16894 17075 17251 17488 17499 17703 17730 17772 17819 17990 18019 18387 18601 18769 19283 19433 19700 19746 19883 20008 20099 21991 22659 23060 23078 23210 25132 25392 25472 25597 25742 25932 26017 26058 26065 26088 26238 26259 26270 26292 26334 26396 26509 26606 26859 26902 26965 26976 27006 27023 27079 27084 27090 27096 27115 27155 27229 27250 27338 27350 27376 27435 27486 27509 27513 27515-27516 27518 27526 27562 27580 27715 27722-27723 27725 27727-27728 27745 27751 27755 27760 27766 28034 28060 28147 28158 28180 28201 28356 28383 28395 28401 28468 28471 28527 28546 28564 28571 28589 28636 31405 31422 31663 32948 32986 32998 33126 33233 33796 33930 33950 34065 34210 35018 35180 35205 35360 35542 35741 35743 35993 36443 36775 36788 37385 38139 38268 38725 38821 38916 43680 44988 45500 46281 46299 46399 46418 46647 47014 47169 47375 48965 49042https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/590/A68?format=asciidefaultJ/A+A/590/A68/tablea1QSO names, coordinates, and emission redshiftsSimbadNameSimbad column added by the CDSmeta.idcharzemQSO emission redshiftsrc.redshiftfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintabsindicates absorption-line measurements in tablea2meta.ref.urlcharSeq[1/303] QSO numbermeta.idintn_Seq[*] Note (1)meta.notecharName1QSO name (COS)meta.id;meta.maincharprimaryName2QSO name (NED)meta.idcharRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination (J2000.0)degpos.eq.dec;meta.maindzAbsorption redshift path for z<0.1src.redshift;arith.difffloatNEDNED column added by the CDSmeta.ref.urlcharJ/A+A/590/A68/tablea2Absorption-line measurements for 59 QSOsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoRow numbermeta.idintName1QSO name (COS)meta.id;meta.maincharzabsAbsorption redshiftsrc.redshiftfloatIonIon (1)phys.atmol.ionStagecharl_EWrestLimit flag on EWrestmeta.code.errorcharEWrest? Restframe equivalent width (or limit)0.1pmspect.line.eqWidthintnullablee_EWrest? Sigma restframe equivalent width0.1pmstat.errorintnullablel_logNLimit flag on logNmeta.code.errorcharlogN? Logarithmic column densitylog(cm**-2)phys.columnDensityfloatnullablee_logN? Sigma logarithmic column densitylog(cm**-2)stat.errorfloatnullable