J/ApJS/177/39ivo://CDS.VizieR/J/ApJS/177/39doi:10.26093/cds/vizier.21770039CDSTripp T.M.Sembach K.R.Bowen D.V.Savage B.D.Jenkins E.B.Lehner N.,Richter P.2017-11-29T11:48:39Z2009-11-07T16:26:34ZCDS support team

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

cds-question@unistra.frspectroscopyultraviolet-astronomyredshiftedquasarsUsing high-resolution ultraviolet spectra of 16 low-z QSOs obtained with the E140M echelle mode of the Space Telescope Imaging Spectrograph, we study the physical conditions and statistics of OVI absorption in the intergalactic medium (IGM) at z<0.5. We identify 51 intervening (z_abs_<z_QSO_) OVI systems comprising 77 individual components, and we find 14 "proximate" systems (z_abs_~z_QSO_) containing 34 components. For intervening systems (components) with rest-frame equivalent width W_r_>30m{AA}, the number of OVI absorbers per unit redshift dN/dz=15.6^+2.9^_-2.4_(21.0^+3.2^_-2.8_), and this decreases to dN/dz=0.9^+1.0^_-0.5_(0.3^+0.7^_-0.3_) for W_r_>300m{AA}. The number per redshift increases steeply as z_abs_ approaches z_QSO_; we find that dN/dz is ~3-10 times higher within 2500km/s of z_QSO_. The most striking difference between intervening and proximate systems is that some proximate absorbers have substantially lower HI/OVI ratios.2008ApJS..177...39Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/177/39CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/23 : Absorption Lines in QSO Spectra (Ellis+ 1978)J/ApJS/77/203 : QSO absorption systems (Junkkarinen+ 1991)J/AJ/112/62 : Quasar absorption-line systems (Tanner+ 1996)J/ApJS/122/355 : Properties of low z QSO absorption systems (Vanden Berk+ 1999)J/ApJ/599/116 : UV properties of absorbed quasars (Vestergaard+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/177/39https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/177/39http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/177/39https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/177/39https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/177/39http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/177/39GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/177/39/list (QSO's list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/177/39/list?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/177/39/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/177/39/list?GETtext/xml+votable180.050000true166.057576.9827780.0055555555555555566/5262 5731 7859 8017 10217 10578 11217 15351 18601 22659 25742 26292 27720 28356 32961 35180https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/177/39?format=asciiUVOpticaldefaultJ/ApJS/177/39/listQSO's listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOQSO namemeta.id;meta.maincharprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainNameQSO JHHMM+DDMM namemeta.idcharSimbadSimbad column added by the CDScharNEDSimbad column added by the CDScharJ/ApJS/177/39/table2OVI absorbers: integrated total equivalent widths and column densitiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOTarget QSO namemeta.id.parentcharzabsAbsorber systemic redshift (1)meta.id;meta.maindoubleIonSpecies and transition used to measure EWr & logNphys.atmol.elementn_Ion[eghjkmo, ] Note(s) on species in notes.dat filemeta.notecharl_EWr[~ ] Limit flag on EWrmeta.code.errorcharEWr? Rest-frame integrated equivalent width0.1pmspect.line.eqWidthfloatnullablee_EWr? Error on EWr0.1pmstat.errorfloatnullablen_EWr[xfil] Note on EWr in notes.dat filemeta.notecharl_logN[>=~ ] Limit flag on logNmeta.code.errorcharlogN? Directly integrated apparent column densityphys.columnDensityfloatnullableE_logN? Positive error on logNstat.error;stat.maxfloatnullablee_logN? Negative error on logNstat.errorfloatnullablen_logN[abdikfln] Note on logN in notes.dat filemeta.notecharn_Vel1[c] Note on component velocity (3)meta.notecharVel1? Velocity centroid of component 1 (2)km/sphys.velocintnullableVel2? Velocity centroid of component 2 (2)km/sphys.velocintnullableVel3? Velocity centroid of component 3 (2)km/sphys.velocintnullableVel4? Velocity centroid of component 4 (2)km/sphys.velocintnullableVel5? Velocity centroid of component 5 (2)km/sphys.velocintnullableVel6? Velocity centroid of component 6 (2)km/sphys.velocintnullableVel7? Velocity centroid of component 7 (2)km/sphys.velocintnullableVel8? Velocity centroid of component 8 (2)km/sphys.velocintnullableVel9? Velocity centroid of component 9 (2)km/sphys.velocintnullableSpecSpectrograph used for the measurementmeta.id;instrcharJ/ApJS/177/39/table3Profile-fitting parameters for intervening and proximate OVI absorbersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOTarget QSO namemeta.id.parentcharzabsAbsorber systemic redshift (1)meta.id;meta.maindoubleClassClassification (2)src.classcharIonSpeciesphys.atmol.elementcharlineFitted linesmeta.noteVel? Velocity centroid (3)km/sphys.velocintnullablee_Vel? Error on Velkm/sstat.errorintnullableu_VelUncertainty flag on Vel (3)meta.code.errorcharb? Doppler parameter (3)km/sspect.dopplerParamintnullableE_b? Positive error on bkm/sstat.error;stat.maxintnullablee_b? Negative error on bkm/sstat.errorintnullableu_bUncertainty flag on b (3)meta.code.errorcharl_logN[>~ ] Limit flag on logNmeta.code.errorcharlogN? Column density of individual components (4)log(cm**-2)phys.columnDensityfloatnullablee_logN? Error on logNlog(cm**-2)stat.errorfloatnullableu_logNUncertainty flag on logN (3)meta.code.errorcharTypeComponent number (type) (5)meta.idcharNote? See comments in "appendix.dat" filemeta.noteintnullableJ/ApJS/177/39/notesNotes from table 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoteNote designationmeta.notecharTextText of notemeta.noteJ/ApJS/177/39/appendixAppendix: comments on line identification, blending, hot pixel contamination, and saturation in individual systemsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoteNote numbermeta.note;meta.mainintprimaryTextText of notemeta.noteJ/ApJS/177/39/table7*Column density ratios and temperature constraints of well-aligned components in intervening OVI absorbersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOTarget QSO namemeta.id.parentcharzabsAbsorption system redshiftmeta.id;meta.maindoubleVelVelocity of the particular component (1)km/sphys.velocintl_logTbLimit flag on logTbmeta.code.errorcharlogTbTemperature upper limit, OVI only (2)log(K)phys.temperaturefloatl_logTLimit flag on logTmeta.code.errorcharlogT3{sigma} upper limit on T, OVI only (3)log(K)phys.temperaturefloatlogTb2? Best measurement of the gas temperature, HI+OVI (4)log(K)phys.temperaturefloatnullablel_logT2Limit flag on logT2meta.code.errorcharlogT2? 3{sigma} upper limit on the temperature, HI+OVI (5)log(K)phys.temperaturefloatnullableb? Nonthermal broadening component corresponding to logTb2km/sphys.velocintnullablelogN(H/O)Log of the HI/OVI column-density ratiophys.density;arith.ratiofloatl_logN(C/O)Limit flag on logNC/Ometa.code.errorcharlogN(C/O)? Log of the CIII/OVI column-density ratiophys.density;arith.ratiofloatnullableClassAbsorber classification (6)src.classchar