J/ApJ/923/223ivo://CDS.VizieR/J/ApJ/923/223doi:10.26093/cds/vizier.19230223CDSZhu Y.Becker G.D.Bosman S.E.I.Keating L.C.Christenson H.M.,Banados E.Bian F.Davies F.B.D'Odorico V.Eilers A.-C.Fan X.,Haehnelt M.G.Kulkarni G.Pallottini A.Qin Y.Wang F.Yang J.2023-10-03T13:08:16Z2023-07-27T13:28:59ZCDS support team

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

cds-question@unistra.frspectroscopyultraviolet-astronomyquasarsredshiftedvisible-astronomyintergalactic-mediumWe present a new investigation of the intergalactic medium (IGM) near the end of reionization using "dark gaps" in the Ly{alpha} forest. Using spectra of 55 QSOs at z_em_>5.5, including new data from the XQR-30 VLT Large Programme, we identify gaps in the Ly{alpha} forest where the transmission averaged over 1 comoving h^-1^ Mpc bins falls below 5%. Nine ultralong (L>80h^-1^Mpc) dark gaps are identified at z<6. In addition, we quantify the fraction of QSO spectra exhibiting gaps longer than 30h^-1^Mpc, F_30_, as a function of redshift. We measure F_30_~0.9, 0.6, and 0.15 at z=6.0, 5.8, and 5.6, respectively, with the last of these long dark gaps persisting down to z~5.3. Comparing our results with predictions from hydrodynamical simulations, we find that the data are consistent with models wherein reionization extends significantly below redshift six. Models wherein the IGM is essentially fully reionized that retain large-scale fluctuations in the ionizing UV background at z<~6 are also potentially consistent with the data. Overall, our results suggest that signatures of reionization in the form of islands of neutral hydrogen and/or large-scale fluctuations in the ionizing background remain present in the IGM until at least z~5.3.2021ApJ...923..223Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/923/223CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/863/92 : LAE cand. at z~5.7 in QSO J0148+0600 field (Becker+, 2018)J/ApJ/883/163 : OI abs. search in Keck & VLT sp. of 199 QSOs (Becker+, 2019)J/MNRAS/488/1035 : AGN UV luminosity function (Kulkarni+, 2019)J/ApJ/873/35 : Gemini GNIRS NIR sp. of 50 QSOs at z>~5.7 (Shen+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/923/223https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/923/223http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/923/223https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/923/223https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/923/223http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/923/223GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/923/223/table1 (QSO spectra used in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/923/223/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/923/223/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/923/223/table1?GETtext/xml+votable180.050000true331.7921883-4.28228780.0055555555555555566/471 2187 4279 4507 4662 5440 5630 7326 8598 8713 9831 10756 12576 16554 17068 17358 17504 17872 18088 18155 18242 18310 18751 19008 19849 20116 20273 21872 23304 23519 25375 25844 26239 26524 26650 27041 27440 27676 27700 30036 30849 30906 33277 34762 35100 35304 35615 35675 36300 44463 44753 44984 48313 48715https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/923/223?format=asciiUVOpticaldefaultJ/ApJ/923/223/table1QSO spectra used in this workSimbadNameSimbad column added by the CDSmeta.idcharnullableSeq[1/55] Runing sequence numbermeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOQSO designationmeta.id;meta.maincharprimaryzem[5.5/6.6] QSO redshiftsrc.redshiftfloatr_zemzem reference (1)meta.ref;pos.framecharSourceSource of the spectrum used for dark gap statistics (2)meta.notecharInstInstrument ("X-Shooter" or "ESI")meta.id;instrcharS/N[21/224] Continuum signal-to-noise ratio (3)stat.snr;spect.continuumintB19Display data from Becker+ 2019, J/ApJ/883/163meta.ref.urlintnullableNdgNumber of dark gaps for this QSO (link to Table 2)meta.numberintnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/923/223/table2Properties of dark gapsQSOQSO namemeta.id.parentcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/1329] Index of the dark gapmeta.id;meta.mainintzBlue[4.6/6.5] Redshift of the dark gap's blue endsrc.redshift;pos.heliocentricfloatf_zBlueFlag on zBlue (1)meta.codecharzRed[4.6/6.5] Redshift of the dark gap's red endsrc.redshift;pos.heliocentricfloatf_zRedFlag on zRed (1)meta.codecharl_L[>= ] Limit flag on Lmeta.code.errorcharL[1/169] Dark gap length in comoving Mpc/h1.475Mpcpos.distance;phys.sizeintf_LFlag on L (1)meta.codecharl_TauEff[>= ] Limit flag on TauEffmeta.code.errorcharTauEff[1.4/8.7] Effective opacity of the dark gapphys.absorption.coefffloate_TauEff[0.01/0.5]? Uncertainty in TauEffstat.errorfloatnullablezMetalAbsRedshift(s) of metal absorber(s) in the dark gap, if anysrc.redshift;pos.heliocentricchar