J/ApJ/894/142ivo://CDS.VizieR/J/ApJ/894/142doi:10.26093/cds/vizier.18940142CDSQu Z.Bregman J.N.Hodges-Kluck E.Li J.-T.Lindley R.2022-01-19T13:10:08Z2021-10-22T13:16:17ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiintergalactic-mediummilky-way-galaxyspectroscopyultraviolet-astronomyWe develop a kinematical model for the Milky Way SiIV-bearing gas to determine its density distribution and kinematics. This model is constrained by a column density line-shape sample extracted from the Hubble Space Telescope/Cosmic Origins Spectrograph archival data, which contains 186 active galactic nucleus sight lines. We find that the SiIV ion density distribution is dominated by an extended disk along the z-direction (above or below the midplane), i.e., n(z)=n_0_exp(-(z/z_0_)^0.82^), where z_0_ is the scale height of 6.3_-1.5_^+1.6^kpc (northern hemisphere) and 3.6_-0.9_^+1.0^kpc (southern hemisphere). The density distribution of the disk in the radial direction shows a sharp edge at 15-20kpc given by, n(r_XY_)=n_0_exp(-(r_XY_/r_0_)^3.36^), where r_0_~12.5+/-0.6kpc. The difference of density distributions over r_XY_ and z directions indicates that the warm gas traced by SiIV is mainly associated with disk processes (e.g., feedback or cycling gas) rather than accretion. We estimate the mass of the warm gas (within 50kpc) is log(M(50kpc)/M_{sun}_)~8.1 (assuming Z~0.5Z_{sun}_), and a 3{sigma} upper limit of log(M(250kpc)/M_{sun}_)~9.1 (excluding the Magellanic system). Kinematically, the warm gas disk is nearly co-rotating with the stellar disk at v_rot_=215+/-3km/s, which lags the midplane rotation by about 8km/s/kpc (within 5kpc). Meanwhile, we note that the warm gas in the northern hemisphere has significant accretion with vacc of 69+/-7km/s at 10kpc (an accretion rate of -0.60_-0.13_^+0.11^M_{sun}_/yr), while in the southern hemisphere, there is no measurable accretion, with an upper limit of 0.4M_{sun}_/yr.2020ApJ...894..142Qhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/894/142CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/ApJS/136/631 : IUE absorption toward 164 early-type stars (Savage+, 2001)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/168/213 : Ionization states and cooling efficiencies (Gnat+, 2007)J/ApJS/176/59 : FUSE survey of OVI in the disk of MW (Bowen+, 2008)J/ApJ/702/1472 : Column densities for HI, SiIV, CIV... (Savage+, 2009)J/ApJ/727/46 : Highly ionized plasmas in the Milky Way (Lehner+, 2011)J/ApJ/749/157 : FUV spectra of Galactic corona sight lines (Wakker+, 2012)J/MNRAS/449/3263 : Extended galaxy halo gas through HI and OVI (Johnson+, 2015)J/ApJ/804/79 : HST/COS obs. of QSOs within 600kpc of M31 (Lehner+, 2015)J/ApJ/832/118 : Emission-line spectroscopy in NGC 891 (Boettcher+, 2016)J/ApJS/228/11 : Time-dependent cooling in photoionized plasma (Gnat, 2017)J/ApJS/233/20 : CGM-MASS. II. New XMM data for 6 spirals (Li+, 2017)J/A+A/607/A48 : AGN data and absorption-line measurements (Richter+, 2017)J/ApJ/871/151 : METAL Hubble program. I. (Roman-Duval+, 2019)J/ApJ/871/35 : HST/COS spectra of QSOs with SiIV data (Zheng+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/894/142https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/894/142http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/894/142https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/894/142https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/894/142http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/894/142GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/894/142/table1 (The column density measurements of the selected SiIV sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/894/142/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/894/142/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/894/142/table1?GETtext/xml+votable180.050000true226.47653.75290.0055555555555555566/2245 2414 2584 2610 2621 2733 4506 4821 5091 5123 5203 5246 5262 5274 5312 5355 5391 5409 5423 5481 5570 5687 5731 5820-5821 5876 5929 5964 5988 6021 6081 6104 6515 6606 7277 7460 7510 7642 7896 7903 7998 8071 8216 8282 8299 8469 8528 8641 8755 8838 8845 8915 8918 8922 8939 9031 9038 9064 9146 9192 9348 9457 10162 10624 10659 10691 10927 11013 11217 11327 11388 11435 11456 11460 11490 11557 11596 11668 11781 12380 15247 15351 16447 17075 17186 17203 17488 17521 17730 17819 17990 18601 18786 18803 19147 19283 19700 19730 19746 19767 19909 19932 20079 20269 20290 22659 25132 25472 25742 25932 26270 26292 26297 26453 26509 26859 26902 27023 27155 27251 27349-27350 27514 27562 27720 27723 27765 27823 27862 28060 28083 28356 28471 28517 28589 28636 29398 30071 30134 31663 33233 33796 33930 33950 34064 34210 34881 35018 35180 35205 35360 35542 35741 35743 35992 36313 36443 36775 36786 38268 38916 40213 44988 45341 45500 46143 46281 46299 46412 46418 46444 46555 46647 46795 47014 47169 47375 47510 48965 49042https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/894/142?format=asciiUVdefaultJ/ApJ/894/142/table1The column density measurements of the selected SiIV sampleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSight line identifiermeta.id;meta.maincharGLON[2.8/358.7] Galactic longitudedegpos.galactic.lonGLAT[-83.7/82.1] Galactic latitudedegpos.galactic.latS/Ns[9/153] Signal-to-Noise of strong line continuumstat.snrintS/Nw[7/158] Signal-to-Noise of weak line continuumstat.snrintVmin[-500/270] Lower bound of absorption componentkm/sphys.absorption;stat.minintVmax[-400/410] Upper bound of absorption componentkm/sphys.absorption;stat.maxintl_logNUpper limit flag on logN (1)meta.code.errorcharlogN[12.36/14.1] Log total component column densitylog(cm**-2)phys.columnDensityfloate_logN[0/0.43] Uncertainty in logNlog(cm**-2)stat.errorfloatVc[-450/339] Component line centroidkm/sspect.dopplerVelocfloate_Vc[0.3/20] Uncertainty in Vckm/sstat.error;pos.cartesian.yfloatNEDNED column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexed