J/ApJ/857/126ivo://CDS.VizieR/J/ApJ/857/126doi:10.26093/cds/vizier.18570126CDSLau M.W.Prochaska J.X.Hennawi J.F.2023-12-14T01:16:17Z2023-09-29T09:07:31ZCDS support team

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

cds-question@unistra.frquasarsvisible-astronomyspectroscopyredshiftedultraviolet-astronomyintergalactic-mediumWe examine the kinematics of the gas in the environments of galaxies hosting quasars at z~2. We employ 148 projected quasar pairs to study the circumgalactic gas of the foreground quasars in absorption. The sample selects foreground quasars with precise redshift measurements, using emission lines with precision <~300km/s and average offsets from the systemic redshift <~|100km/s|. We stack the background quasar spectra at the foreground quasar's systemic redshift to study the mean absorption in C II, C IV, and Mg II. We find that the mean absorptions exhibit large velocity widths {sigma}_v_~300km/s. Further, the mean absorptions appear to be asymmetric about the systemic redshifts. The mean absorption centroids exhibit small redshift relative to the systemic {delta}v~+200km/s, with large intrinsic scatter in the centroid velocities of the individual absorption systems. We find the observed widths are consistent with gas in gravitational motion and Hubble flow. However, while the observation of large widths alone does not require galactic-scale outflows, the observed offsets suggest that the gas is on average outflowing from the galaxy. The observed offsets also suggest that the ionizing radiation from the foreground quasars is anisotropic and/or intermittent.2018ApJ...857..126Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/857/126CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)J/AJ/130/381 : Blueshifted [O III] emission (Boroson+, 2005)J/ApJ/651/61 : Optically thick absorbers near luminous QSOs (Hennawi+, 2006)J/MNRAS/391/1457 : Lyman{alpha} forest in QSO pairs (Kirkman+, 2008)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJ/740/91 : Ly{alpha} and OVI in galaxies around quasars (Prochaska+, 2011)J/ApJ/762/L19 : Quasar pairs spectroscopy (Prochaska+, 2013)J/MNRAS/430/425 : VLT LBG Redshift Survey. III. (Bielby+, 2013)J/ApJ/776/136 : QPQ VI. HI absorption of z~2 quasars (Prochaska+, 2013)J/ApJ/794/156 : MgII/FeII absorption profile for 0.3<z<1.4 gal. (Rubin+, 2014)J/ApJ/796/140 : Circumgalactic medium surrounding z~2 QSOs (Prochaska+, 2014)J/MNRAS/452/2553 : Sample of foreground-background QSO pairs (Johnson+, 2015)J/ApJ/818/30 : Lag measurements for 15 z<0.8 QSOs from SDSS-RM (Shen+, 2016)J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)J/MNRAS/462/3285 : XQ-100. X-shooter quasar spectra (Perrotta+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/857/126https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/857/126http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/857/126https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/857/126https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/857/126http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/857/126GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/857/126/table1 (Properties of the projected quasar pairs in the QPQ9 sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/857/126/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/857/126/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/857/126/table1?GETtext/xml+votable180.050000true8.5960417-10.83388890.0055555555555555566/2150 2561 4115 4185 4203 4558 4615 4850 4972 5113 5135 5162 5229 5385 5437 5499 5501 5503 5709 5761 5772 5798 5823 5839 5846 5851 5855 5868 5871 5874 5900 5935 5944 6017 6019 6045 6137 6217 6396 6409 6441 6464 6470-6471 6523 6525 6541 6604 6628 7202 7204 7206 7227 7295 7332 7344 7362 7451 7475 7499 7505 7522 8328 8334 8464 8489 8534 8553 8650 8756 8871 8953 9118 9138 9182 9280 9307 9736 9969 9973 9986 10016 10311 10495 10683 10707 10724 10743 10856 10979 11019 11042 11049 11109 11188 11193 11410 11446 11907 12788 17233 17693 17727 17741 17745 17753 17763 17765 17829 18021-18022 18069 18778 18947 19387 19738 20424 20430 21844 23104 23189 25953 25972 26054 26268 26483 27254-27255 27281 27297 27307 27309 27345 27496 27654 27682 27701 27708 27803 27863 27879 28111 28350 28424 28538 28667https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/857/126?format=asciiUVOpticaldefaultJ/ApJ/857/126/table1Properties of the projected quasar pairs in the QPQ9 sampleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOfgForeground quasar designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharzfg[1.6/3.82] Foreground redshiftsrc.redshift;pos.heliocentricfloatn_zfgThe emission line analyzed for measuring z_fg_meta.notecharQSObgBackground quasar designation (JHHMMSS.ss+DDMMSS.s)meta.id.assoccharzbg[1.64/4.2] Background redshiftsrc.redshift;pos.heliocentricfloatTelzbgBackground quasar instrumentmeta.id;instrcharSep[32/299] Projected separation at the foreground quasar's redshiftkpcpos.angDistanceintgUV[60/34208] The enhancement in the UV flux relative to the extragalactic UV background, g_UV_phot.flux;em.UVintQPQ6Display data from QPQ6 (Prochaska+ 2013, J/ApJ/776/136)meta.ref.urlintnullableSloanDisplay the online SDSS-DR17 data for the nearest object of the foreground quasarmeta.ref.urlchar_RAPositions from foreground quasar names (right ascension part)degpos.eq.ra;meta.main_DEPositions from foreground quasar names (declination part)degpos.eq.dec;meta.main