J/ApJ/776/136ivo://CDS.VizieR/J/ApJ/776/136doi:10.26093/cds/vizier.17760136CDSProchaska J.X.Hennawi J.F.Lee K.-G.Cantalupo S.Bovy J.,Djorgovski S.G.Ellison S.L.Lau M.W.Martin C.L.Myers A.,Rubin K.H.R.Simcoe R.A.2017-06-27T06:37:56Z2015-04-27T13:25:27ZCDS support team

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

cds-question@unistra.frquasarsredshiftedspectroscopyline-intensitiesWith close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We use a sample of 650 projected quasar pairs to study the HI Ly{alpha} absorption transverse to luminous, z~2 quasars at proper separations of 30kpc<R_{perp}_<1Mpc. In contrast to measurements along the line-of-sight, regions transverse to quasars exhibit enhanced HI Ly{alpha} absorption and a larger variance than the ambient intergalactic medium, with increasing absorption and variance toward smaller scales. Analysis of composite spectra reveals excess absorption characterized by a Ly{alpha} equivalent width profile W=2.3{AA} (R_{perp}_/100kpc)^-0.46^. We also observe a high (=~60%) covering factor of strong, optically thick HI absorbers (HI column N_HI_>10^17.3^/cm2) at separations R_{perp}_<200kpc, which decreases to ~20% at R_{perp}_=~1Mpc, but still represents a significant excess over the cosmic average. This excess of optically thick absorption can be described by a quasar-absorber cross-correlation function {xi}_QA_(r)=(r/r_0_)^{gamma}^ with a large correlation length r_0_=12.5_-1.4_^+2.7^h^-1^Mpc (comoving) and {gamma}=1.68_-0.30_^+0.14^. The HI absorption measured around quasars exceeds that of any previously studied population, consistent with quasars being hosted by massive dark matter halos M_halo_{approx}10^12.5^M_{sun}_ at z~2.5. The environments of these massive halos are highly biased toward producing optically thick gas, and may even dominate the cosmic abundance of Lyman limit systems and hence the intergalactic opacity to ionizing photons at z~2.5. The anisotropic absorption around quasars implies the transverse direction is much less likely to be illuminated by ionizing radiation than the line-of-sight.2013ApJ...776..136Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/776/136CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)J/ApJ/775/78 : Lyman limit absorption systems in QSOs (Fumagalli+, 2013)J/MNRAS/430/425 : VLT LBG Redshift Survey. III. (Bielby+, 2013)J/ApJ/765/137 : HST survey for Lyman limit systems. II. (O'Meara+, 2013)J/ApJ/763/37 : Metals in SDSS QSOs. I. 1.5<z<4.5 CIV abs. (Cooksey+, 2013)J/ApJ/762/L19 : Quasar pairs spectroscopy (Prochaska+, 2013)J/A+A/547/L1 : SDSS-III DR9 DLA catalogue (Noterdaeme+, 2012)J/ApJ/755/89 : Metallicities of damped Ly{alpha} systems (Rafelski+, 2012)J/ApJ/740/91 : Ly{alpha} and OVI in galaxies around QSOs (Prochaska+, 2011)J/ApJS/195/16 : HST survey for Lyman limit systems. I. (O'Meara+, 2011)J/ApJ/736/42 : HST QSO Catalog (Ribaudo+, 2011)J/MNRAS/414/28 : VLT Lyman-break gal. redshift survey. II. (Crighton+, 2011)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJ/719/1672 : SDSS binary quasars at high redshift. I. (Hennawi+, 2010)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/ApJ/718/392 : SDSS Lyman limit systems at z~3.5 (Prochaska+, 2010)J/MNRAS/392/1539 : Metal absorption systems in pairs of QSOs (Tytler+, 2009)J/MNRAS/391/1457 : Lyman{alpha} forest in QSO pairs (Kirkman+, 2008)J/ApJS/175/29 : Spectroscopy of QSO pairs (Marble+, 2008)J/ApJ/675/1002 : Proximate DLA systems in SDSS-DR5 (Prochaska+, 2008)J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)J/ApJ/658/99 : Pairs of QSO in SDSS-DR4 (Myers+, 2007)J/ApJ/651/61 : Opt. thick absorbers near luminous QSOs (Hennawi+, 2006)J/ApJ/648/L97 : 2 QSOs supersolar super-Lyman limit syst. (Prochaska+ 2006)J/AJ/131/1 : Binary quasars in the SDSS (Hennawi+, 2006)J/ApJ/635/123 : The SDSS-DR3 damped Ly{alpha} survey (Prochaska+, 2005)J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004)http://www.sdss.org/ : SDSS home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/776/136https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/776/136http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/776/136https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/776/136https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/776/136http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/776/136GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/776/136/qpq6 (Quasars Probing Quasars VI (QPQ6) redshifts and HI measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/776/136/qpq6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/776/136/qpq6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/776/136/qpq6?GETtext/xml+votable180.050000true0.549-5.48566670.005555555555555556Cone search capability for table J/ApJ/776/136/table2 (Journal of observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/776/136/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/776/136/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/776/136/table2?GETtext/xml+votable180.050000true7.0108333-10.82666670.0055555555555555566/4096 4098 4103 4115 4136 4185 4229 4269 4346 4608 4626 4631 4649 4671 4710 4738 4757 4762 4767 4795 4800 4952 5002 5025 5039 5047 5049 5092 5162 5327 5331 5342 5357 5359 5360 5362 5410 5424 5428 5430 5442 5445 5454 5476 5494 5504 5517 5523 5529 5551 5554 5661 5669 5676 5686 5704 5709 5715 5722 5725 5739 5748 5754 5772 5828 5846 5855 5920 5944 5971 6068 6166 6209 6210 6211 6217 6226 6230 6238 6246 6265 6345 6353 6361 6363 6385 6409 6414 6422 6431 6432 6433 6441 6449 6454 6464 6469 6470 6471 6489 6504 6505 6523 6534 6536 6539 6541 6549 6551 6552 6576 6579 6604 6617 6622 6624 6625 6633 6634 6637 6641 6649 6652 6737 7256 7305 7337 7440 7503 8192 8194 8212 8220 8223 8231 8234 8243 8262 8325 8330 8338 8414 8461 8473 8489 8493 8494 8508 8536 8537 8538 8547 8550 8552 8553 8561 8583 8621 8623 8651 8666 8702 8787 8953 8965 8983 8991 9033 9067 9081 9107 9118 9131 9135 9139 9144 9182 9222 9225 9272 9278 9283 9307 9317 9332 9350 9360 9369 9375 9378 9381 9395 9419 9446 9451 9477 9486 9512 9729 9821 9858 9864 9958 9969 9973 9978 10016 10311 10362 10364 10365 10366 10386 10429 10446 10451 10454 10459 10465 10469 10470 10472 10492 10495 10496 10497 10498 10501 10506 10511 10512 10513 10529 10540 10547 10601 10625 10628 10632 10635 10636 10658 10724 10743 10765 10776 10779 10787 10788 10789 10791 10796 10798 10799 10801 10805 10808 10827 10831 10858 10859 10860 10883 10904 10912 10914 11278 11294 11446 11803 11907 12352 12364 12369 12371 12374 12613 17223 17229 17233 17359 17396 17661 17663 17686 17693 17728 17732 17734 17741 17742 17753 17758 17760 17764 17766 17768 17770 17772 17773 17791 17807 17811 17820 17829 17830 17831 17836 17840 17847 17877 17893 17900 17981 18002 18003 18010 18011 18020 18022 18024 18025 18026 18028 18037 18039 18043 18051 18054 18061 18065 18071 18073 18076 18082 18083 18084 18086 18087 18088 18091 18093 18100 18112 18126 18192 18202 18204 18218 18240 18283 18289 18381 18408 18416 18685 18740 18743 18749 18751 18769 18782 18798 18800 18812 18843 18855 18858 18860 18866 18879 18882 18947 19028 19029 19034 19035 19043 19047 19052 19053 19058 19067 19068 19087 19089 19093 19094 19108 19111 19117 19137 19138 19160 19167 19178 19182 19192 19202 19209 19353 19354 19380 19387 19388 19457 19692 21844 21887 22006 22367 23104 23144 23146 23189 25583 25592 25909 25924 25929 25943 25953 25956 25957 25961 25968 25972 25977 25980 25996 25998 26010 26022 26025 26028 26033 26058 26064 26074 26096 26098 26167 26191 26193 26195 26217 26224 26225 26230 26234 26235 26237 26238 26245 26246 26248 26257 26261 26262 26264 26268 26277 26283 26297 26308 26313 26315 26324 26338 26343 26346 26350 26353 26368 26385 26391 26410 26420 26955 26958 26965 26966 26968 26983 26990 27006 27017 27023 27030 27044 27052 27054 27069 27075 27080 27191 27211 27212 27218 27220 27221 27224 27233 27243 27261 27263 27281 27286 27289 27297 27298 27299 27302 27303 27309 27311 27316 27322 27341 27342 27352 27353 27356 27360 27396 27427 27430 27438 27439 27459 27528 27652 27654 27682 27683 27686 27701 27714 27782 27803 27932 28041 28082 28153 28332 28539 28595 28601 28622 28624 28625 28635 28637 28640 28649 28651 31357 31411 31419 31420 31444 31447 31452 31454 31455 31460 31466 31467 31530 31661 31691 31716 32395 32416 32426 32431 32435 32442 32443 32457 32461 32463 32474 32481 32500 32510 32672 32680 36793 36862 45045 45047https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/776/136?format=asciiOpticaldefaultJ/ApJ/776/136/qpq6Quasars Probing Quasars VI (QPQ6) redshifts and HI measurementsQfgName of the foreground quasar in SIMBADmeta.idcharQbgName of the background quasar in SIMBADmeta.idcharl_WLyaLimit flag on WLyameta.code.errorchardelv[-1733/1553]? Velocity offset (6)km/sphys.veloc;arith.diffintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintf/g-QForeground quasar identifiermeta.id;meta.maincharL912[28/32]? Log of 912{AA} luminosity; erg/s/cm^2^/{AA} (2)log(cW.m**-2.nm**-1)phys.luminosity;em.IRfloatnullableLbol[45/48]? Log of bolometric luminosity; erg/s/cm^2^ (2)log(mW.m**-2)phys.luminosityfloatnullableb/g-QBackground quasar identifiermeta.id.assoccharzbg[1.7/4.9] Background redshiftsrc.redshift;pos.heliocentricfloatNqNumber of foreground quasars associated in QPQ6meta.numberintnullableb[31/999] Impact parameter R_{perp}_kpcsrc.impactParamintgUV[2/17964]? Enhancement in flux relative to the extragalactic UV background (2)phot.flux;arith.ratiointnullableInstSource spectrum (G1)meta.id;instrcharLinesEmission lines used in zemmeta.id;spect.linecharzfg[1.6/4.5] Emission line derived redshiftsrc.redshift;pos.heliocentricfloate_zfg[272/794] Uncertainty in zfgkm/sstat.errorintS/N[6/205] Signal-to-noise per rest-frame {AA} (3)stat.snrint<F2000>[0/1.2] Average flux (4)phot.fluxfloatDelF[-0.5/1] Value defined in Equ. 4 (5)phot.flux;arith.ratiofloatLWave[3204/6615]? Lower wavelength of Ly{alpha} analysis ({AA})0.1nmem.wlfloatnullableUWave[3217/6634]? Upper wavelength of Ly{alpha} analysis ({AA})0.1nmem.wlfloatnullableWLya[0.2/23.7]? Rest equivalent width (7)0.1nmspect.line.eqWidthfloatnullablee_WLya[0.01/0.3]? Uncertainty in WLya0.1nmstat.errorfloatnullablel_logNHLimit flag on logNHmeta.code.errorcharlogNH[14.3/21.3]? Log of H I column densitylog(cm**-2)phys.columnDensityfloatnullablee_logNH[0.1/0.4]? Uncertainty in logNHlog(cm**-2)stat.errorfloatnullableOT[-1/1]? Optical thick flag (8)meta.codeintnullableDR9QSources from Paris+, 2012, VII/269, within 2"meta.ref.urlintnullableObsDisplay the observation logmeta.codeintnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RASimbad column added by the CDSdegpos.eq.ra;meta.main_DESimbad column added by the CDSdegpos.eq.dec;meta.mainJ/ApJ/776/136/table2Journal of observationsObsObservatorymeta.id;instr.obstycharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintb/g-QBackground quasar identifier (1)meta.id.assoccharInstInstrument (2)meta.id;instrcharDateObservation date (3)time.epoch;obsnullableExp[300/16800] Exposure time (4)stime.duration;obs.exposureintNqNumber of foreground quasars associated in QPQ6meta.numberintnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlchar_RAPostions from background quasar identifier (right ascension part)degpos.eq.ra;meta.main_DEPostions from background quasar identifier (declination part)degpos.eq.dec;meta.main