J/ApJ/804/79ivo://CDS.VizieR/J/ApJ/804/79doi:10.26093/cds/vizier.18040079CDSLehner N.Howk J.C.Wakker B.P.2017-12-07T07:27:46Z2015-09-17T10:52:07ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopyultraviolet-astronomyquasarsWe demonstrate the presence of an extended and massive circumgalactic medium (CGM) around Messier 31 using archival HST Cosmic Origins Spectrograph ultraviolet spectroscopy of 18 QSOs projected within two virial radii of M31 (R_vir_=300kpc). We detect absorption from SiIII at -300<~V_LSR_<~-150km/s toward all three sightlines at R<~0.2R_vir_, 3 of 4 sightlines at 0.8<~R/R_vir_<~1.1, and possibly 1 of 11 at 1.1<R/R_vir_<~1.8. We present several arguments that the gas at these velocities observed in these directions originates from the M31 CGM rather than the Local Group or Milky Way CGM or Magellanic Stream. We show that the dwarf galaxies located in the CGM of M31 have very similar velocities over similar projected distances from M31. We find a non-trivial relationship only at these velocities between the column densities (N) of all the ions and R, whereby N decreases with increasing R. At R<0.8R_vir_, the covering fraction is close to unity for Si III and C IV (f_c_~60%-97% at the 90% confidence level), but drops to f_c_<~10%-20% at R>~R_vir_. We show that the M31 CGM gas is bound, multiphase, predominantly ionized, and is more highly ionized gas at larger R. We estimate using Si II, Si III, and Si IV, a CGM metal mass of >~2x10^6^M_{sun}_ and gas mass of >~3x10^9^(Z_{sun}_/Z)M_{sun}_ within 0.2R_vir_, and possibly a factor of ~10 larger within R_vir_, implying substantial metal and gas masses in the CGM of M31.2015ApJ...804...79Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/804/79CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/567/A71 : M31 Herschel images (Viaene+, 2014)J/MNRAS/445/2061 : Absorption in multiphase CGM (Liang+, 2014)J/ApJ/770/138 : Metallicities of Lyman limit systems and DLA (Lehner+, 2013)J/ApJ/758/133 : Metallicity profile of M31 HII region & PN (Sanders+, 2012)J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/ApJ/749/157 : FUV spectra of Galactic corona sight lines (Wakker+, 2012)J/ApJ/745/156 : M31 Cepheids with HST/WFC3 (Riess+, 2012)J/ApJ/740/91 : Ly{alpha} & OVI in galaxies around QSOs (Prochaska+, 2011)J/MNRAS/415/1105 : Intermediate high-velocity clouds distances (Smoker+, 2011)J/ApJ/727/46 : Highly ionized plasmas in the Milky Way (Lehner+, 2011)J/ApJ/714/1521 : Spectroscopy of galaxies around distant QSOs (Chen+, 2010)J/MNRAS/399/728 : UV-bright sources behind M31 halo (Fittingoff+, 2009)J/ApJ/703/614 : UV star-forming regions in M31 (Kang+, 2009)J/ApJ/702/940 : Radio and UV spectra of HVC toward the MC (Lehner+, 2009)J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)J/ApJS/182/378 : HI and OVI absorbers in nearby Universe (Wakker+, 2009)J/ApJS/168/213 : Ionization states and cooling efficiencies (Gnat+, 2007)J/ApJS/163/282 : Molecular hydrogen column densities (Wakker+, 2006)J/A+A/417/421 : WSRT wide-field HI survey. II. (Braun+, 2004)J/ApJS/146/125 : O VI in the galactic halo (Savage+, 2003)J/ApJS/146/1 : O VI absorption in FUSE survey (Wakker+, 2003)J/ApJS/136/463 : Distances and metallicities of HVCs and IVCs (Wakker, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/804/79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/804/79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/804/79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/804/79https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/804/79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/804/79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/804/79/table1 (Sample of COS G130M-G160M targets piercing the circumgalactic medium (CGM) of M31)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/804/79/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/804/79/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/804/79/table1?GETtext/xml+votable180.050000true12.0839.690.0055555555555555566/134 180 526 552 2414 2621 2663 2754 12752 13414 17819 17898 17990 18019 18125 18302 18387 18769 18770 18809 19283 19433 19567 19700 19730 19746 19883 20008 20099https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/804/79?format=asciiUVdefaultJ/ApJ/804/79/table1Sample of COS G130M-G160M targets piercing the circumgalactic medium (CGM) of M31NameTarget namemeta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSet[R] R=rejected sample (1)meta.codecharNlNumber of lines studied for this QSOmeta.numberintnullableRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainzem[0.009/2.7] Emission redshiftsrc.redshiftfloatR[25/527] Planar distance from M31 centerkpcpos.distanceintInstCOS instrumentinstrcharS/N[0/24] Signal to noise ratiostat.snrintNote[2/9]? Rejection reason (2)meta.noteintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharNEDSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/804/79/table2Kinematics and column densitiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameQSO identifiermeta.id;meta.maincharR[25/527] Planar distance from M31 centerkpcpos.distanceint<Vlsr>[-274.3/-204.1]? Average LSR velocity (1)km/sphys.veloc;pos.lsrfloatnullablee_<Vlsr>? The 1{sigma} uncertainty in <Vlsr>km/sstat.error;phys.veloc;pos.lsrfloatnullableElSpecies identifier (2)phys.atmol.ionStagecharlambdaSpecies wavelength ({AA})0.1nmem.wlintv1[-321/-260] Lower LSR velocity (3)km/sspect.dopplerVeloc;stat.minintv2[-220/-130] Upper LSR velocity (3)km/sspect.dopplerVeloc;stat.maxint<v>[-274.3/-188.7]? Average LSR velocity from the first momentkm/sspect.dopplerVeloc;pos.lsrfloatnullableu_<v>Uncertainty flag on <v> due to blendingmeta.code.errorchare_<v>[0.8/15.5]? Uncertainty in <v>km/sstat.errorfloatnullablel_logN[<=> ] Limit flag on logN (4)meta.code.errorlogN[12.1/14.6] Log column density in Specieslog(cm**-2)phys.columnDensityfloatu_logNUncertainty flag on logN due to blendingmeta.code.errorchare_logN[0.01/0.2]? Uncertainty in logNlog(cm**-2)stat.errorfloatnullable