J/ApJ/884/151ivo://CDS.VizieR/J/ApJ/884/151doi:10.26093/cds/vizier.18840151CDSJalan P.Chand H.Srianand R.2022-04-04T09:29:39Z2021-04-20T08:23:07ZCDS support team

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

cds-question@unistra.frquasarsredshiftedvisible-astronomysloan-photometryspectroscopyWe have used spectra of 181 projected quasar pairs at separations <=1.5' from the Sloan Digital Sky Survey Data Release 12 in the redshift range of 2.5-3.5 to probe the proximity regions of the foreground quasars. We study the proximity effect both in the longitudinal and in the transverse directions, by carrying out a comparison of the Ly{alpha} absorption lines originating from the vicinity of quasars to those originating from the general intergalactic medium at the same redshift. We found an enhancement in the transmitted flux within 4Mpc to the quasar in the longitudinal direction. However, the trend is found to be reversed in the transverse direction. In the longitudinal direction, we derived an excess overdensity profile showing an excess up to r<=5Mpc after correcting for the quasar's ionization, taking into account the effect of low spectral resolution. This excess overdensity profile matches with the average overdensity profile in the transverse direction without applying any correction for the effect of the quasar's ionization. Among various possible interpretations, we found that the anisotropic obscuration of the quasar's ionization seems to be the most probable explanation. This is also supported by the fact that all of our foreground quasars happen to be type 1 AGNs. Finally, we constrain the average quasar's illumination along the transverse direction as compared to that along the longitudinal direction to be <=27% (3{sigma} confidence level).2019ApJ...884..151Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/884/151CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)J/A+A/376/28 : Inversion of the HE 1122-1648 UVES spectrum (Rollinde+ 2001)J/MNRAS/335/555 : Lyman-alpha forest of 5 QSOs (Kim+, 2002)J/ApJ/651/61 : Opt. thick absorbers near luminous QSOs (Hennawi+, 2006)J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)J/MNRAS/391/1457 : Lyman{alpha} forest in QSO pairs (Kirkman+, 2008)J/A+A/505/1087 : DLAs in SDSS-DR7 (Noterdaeme+, 2009)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/A+A/547/L1 : SDSS-III DR9 DLA catalogue (Noterdaeme+, 2012)J/MNRAS/435/3306 : Candidate type II QSOs in SDSS III (Alexandroff+, 2013)J/ApJ/776/136 : QPQ VI. HI absorption of z~2 quasars (Prochaska+, 2013)J/ApJ/796/140 : Circumgal. medium surrounding z~2 QSOs (Prochaska+, 2014)J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)J/MNRAS/468/77 : Sample of confirmed quasar pairs (Eftekharzadeh+, 2017)J/ApJ/847/81 : HeII photoionization rates of quasars (Schmidt+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/884/151https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/884/151http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/884/151https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/884/151https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/884/151http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/884/151GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/884/151/table1 (Basic properties of our 181 quasar pairs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/884/151/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/884/151/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/884/151/table1?GETtext/xml+votable180.050000true0.68712.9660.0055555555555555566/4096 4124 4178 4419 4461 4905 4953 4961 5004 5047 5159 5179 5249 5278 5281 5331 5410 5523 5584 5615 5638 5713 5731 5737 5739 5831 5838 5922 6089 6108 6116 6119 6230 6367 6414 6505 6523 6527-6528 6554 6976 7242 7263 7322 7344 7493 7508-7509 8261 8284 8385 8406 8479 8699 8847 8906 9107 9179 9210 9275 9278 9324 9350 9640 9813 9826 9875 10020 10118 10147 10253 10378 10419 10494 10564 10592 10669 10752 10791 10799 10912 10950 11036 11048 11107 11170 11231 11294 11406 11427 11441 11463 11465 11823 11832 11846 12599 13313 13318 13390 17498 17532 17820 17837 17993 18003 18024-18025 18073 18075 18084 18112 18122 18429 18783 18798 18841 18856 18858 18866 19052-19053 19089 19111 19202 19315 19353 19472 19530 19559 19661 19802 19834 19869 19936 20017 20147 20271 21869 25977 26076 26213 26264 26266 26292 26305 26317 26346 26450 26990 27122 27243 27392 27459 27519 27570 27644 27859 27928 27982 28082 28186 28194 28197 28302 28326 28471 28515 31467-31468 31477 31661 31691 32413 32443 32446 32463 36766 36798https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/884/151?format=asciiOpticaldefaultJ/ApJ/884/151/table1Basic properties of our 181 quasar pairsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/181] Running sequential numbermeta.recordintName-bgName of background quasars (JHHMMSS.ss+DDMMSS.ss)meta.id.assoccharz-bg[2.7/3.711] Redshift of background quasarsrc.redshift;pos.heliocentricdoublee_z-bg[0.004/0.006] Error in redshift of background quasarstat.errordoubleL-bg[29/31.2] Log, luminosity at 912{AA} of the background quasar, erg/s/Hzlog(1e-07W.Hz**-1)instr.backgroundfloatrmag-bg[18.3/22.5] r-band magnitude of the background quasarphot.mag;em.opt.RfloatName-fgName of foreground quasars (JHHMMSS.ss+DDMMSS.ss)meta.id;meta.maincharz-fg[2.56/3.46] Redshift of foreground quasarsrc.redshift;pos.heliocentricdoublee_z-fg[0.003/0.006] Error in redshift of foreground quasarstat.errordoubleL-fg[28.8/31.11] Log, luminosity at 912{AA} of the foreground quasar, erg/s/Hzlog(1e-07W.Hz**-1)phys.luminosityfloatrmag-fg[18.4/22] r-band magnitude of the foreground quasarphot.mag;em.opt.RfloatR-perp[26/731] Perpendicular distance between pairs sightline at z-fgkpcpos.angDistanceintSloanDisplay the online SDSS-DR14 data for the nearest object of the foreground quasarmeta.ref.urlchar_RAPositions from background quasar names (right ascension part)degpos.eq.ra;meta.main_DEPositions from background quasar names (declination part)degpos.eq.dec;meta.main