J/ApJ/833/283ivo://CDS.VizieR/J/ApJ/833/283doi:10.26093/cds/vizier.18330283CDSLehner N.O'Meara J.M.Howk J.C.Prochaska J.X.Fumagalli M.2018-09-18T15:28:21Z2018-05-15T17:20:58ZCDS support team

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

cds-question@unistra.frquasarsredshiftedchemical-abundancesgalaxiesspectroscopyh-i-line-emissionvisible-astronomyWe present the first results from our KODIAQ Z survey aimed at determining the metallicity distribution and physical properties of the z>~2 partial and full Lyman limit systems (pLLSs and LLSs; 16.2<=logN_HI_<19), which are probed of the interface regions between the intergalactic medium (IGM) and galaxies. We study 31 HI-selected pLLSs and LLSs at 2.3<z<3.3 observed with Keck/HIRES in absorption against background QSOs. We compare the column densities of metal ions to HI and use photoionization models to assess the metallicity. The metallicity distribution of the pLLSs/LLSs at 2.3<z<3.3 is consistent with a unimodal distribution peaking at [X/H]~-2. The metallicity distribution of these absorbers therefore evolves markedly with z since at z<~1 it is bimodal with peaks at [X/H]~-1.8 and -0.3. There is a substantial fraction (25%-41%) of pLLSs/LLSs with metallicities well below those of damped Ly{alpha} absorbers (DLAs) at any studied z from z<~1 to z~2-4, implying reservoirs of metal-poor, cool, dense gas in the IGM/galaxy interface at all z. However, the gas probed by pLLSs and LLSs is rarely pristine, with a fraction of 3%-18% for pLLSs/LLSs with [X/H]<=-3. We find C/{alpha} enhancement in several pLLSs and LLSs in the metallicity range -2<~[X/H]<~-0.5, where C/{alpha} is 2-5 times larger than observed in Galactic metal-poor stars or high-redshift DLAs at similar metallicities. This is likely caused by preferential ejection of carbon from metal-poor galaxies into their surroundings.2016ApJ...833..283Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/833/283CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/596/768 : Optical depths in 19 QSOs (Schaye+, 2003)J/ApJ/635/123 : The SDSS-DR3 damped Ly{alpha} survey (Prochaska+, 2005)J/ApJ/765/137 : HST survey for Lyman limit systems. II. (O'Meara+, 2013)J/ApJ/676/262 : PKS1302-102 intergalactic absorption system (Cooksey+, 2008)J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)J/ApJ/718/392 : SDSS Lyman limit systems at z~3.5 (Prochaska+, 2010)J/ApJ/721/1 : Keck ESI observations of Ly{alpha} systems (Penprase+, 2010)J/ApJ/755/89 : Metallicities of damped Ly{alpha} systems (Rafelski+, 2012)J/ApJ/770/138 : Metallicities of Lyman limit systems and DLA (Lehner+, 2013)J/ApJ/775/78 : Lyman limit absorption systems in z~3 QSOs (Fumagalli+, 2013)J/MNRAS/435/482 : DLA system from SDSS DR5 (Jorgenson+, 2013)J/ApJ/788/119 : Highly ionized gas of quasar properties (Lehner+, 2014)J/ApJ/794/156 : MgII/FeII absorption profile for 0.3<z<1.4 gal. (Rubin+, 2014)J/MNRAS/445/2061 : Absorption in multiphase circumgal. medium (Liang+, 2014)J/ApJ/804/79 : HST/COS obs. of QSOs within 600kpc of M31 (Lehner+, 2015)J/AJ/150/111 : KODIAQ DR1 (O'Meara+, 2015)J/ApJS/221/2 : Keck+Magellan survey for LLSs. III. (Prochaska+, 2015)J/MNRAS/458/4074 : UVES Advanced Data Products QSO Sample. VI. (Quiret+, 2016)J/ApJ/833/270 : HI-selected-Lyman limit system metallicities (Glidden+, 2016)J/AJ/154/114 : KODIAQ DR2 (O'Meara+, 2017)http://koa.ipac.caltech.edu/workspace/TMP_OTW3Fi_29029/kodiaq29029.html :https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/833/283https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/833/283http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/833/283https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/833/283https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/833/283http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/833/283GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/833/283/table2 (Summary of the HI parameters and metallicities of 26 partial and full Lyman limit systems (pLLSs and LLSs))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/833/283/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/833/283/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/833/283/table2?GETtext/xml+votable180.050000true218.317083331.52397220.0055555555555555566/5272 5723 6070 7857 9112 9138 9272 10063 10312 10405 10843 10994 11596 11786 11925 17510 17749 17813 18406 23210 27578 35496 40274 43903 48610https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/833/283?format=asciiRadioOpticaldefaultJ/ApJ/833/283/table1Average velocities and column densities of the metal ions (for 21 pLLSs and LLSs)zabs[2.3/3.3] Absorption redshift of LLSsrc.redshiftdoublef_Ion[ab] Metal line flag (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKODIAQQuasar designation (JHHMMSS+DDMMSSA)meta.id;meta.maincharlogNHI[16/18.7] Log HI column densitylog(cm**-2)phys.columnDensityfloatIonMetal linephys.atmol.ionStagecharlambda[977/1670]? Transition rest wavelength in Angstroms0.1nmem.wl;phys.atmol.transitionintnullablevmin[-70/-10]? Minimum velocity limitkm/sphys.velocintnullablevmax[10/70]? Maximum velocity limitkm/sphys.velocintnullableva[-25.1/18.1]? Average velocity of metal linekm/sspect.dopplerVelocfloatnullableu_va[:] Quality flag for va (2)meta.code.errorchare_va[0.1/20]? Uncertainty for vakm/sstat.errorfloatnullablel_logNa[<=> ] Limit flag for logNa (2)meta.code.errorcharlogNa[10.7/14.7]? Column density of metal linelog(cm**-2)phys.columnDensity;spect.linefloatnullableu_logNa[:] Quality flag for logNa (2)meta.code.errorchare_logNa[0.01/0.2]? Uncertainty for logNalog(cm**-2)stat.errorfloatnullableJ/ApJ/833/283/table2Summary of the HI parameters and metallicities of 26 partial and full Lyman limit systems (pLLSs and LLSs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSet0: New sample of partial Lyman limit systems (pLLSs) and full Lyman limit systems (LLSs); 1: Sample of pLLSs and LLSs drawn from the literaturemeta.codeintNvNumber of velocity measurements for this QSO (link to table 1)meta.numberintnullableKODIAQQuasar designation (JHHMMSS+DDMMSSA) (1)meta.id;meta.maincharprimaryCDisplay the cloudy results (link to table 6)meta.ref.urlcharzabs[2.1/3.3] Absorption redshift of LLSsrc.redshiftdoublelogNHI[16/18.7] Log HI column density (2)log(cm**-2)phys.columnDensityfloatE_logNHI[+0.01/+0.3] Upper or symmetric uncertainty on logNHI (3)log(cm**-2)stat.error;stat.maxfloate_logNHI[-0.3/-0.2]? Lower uncertainty on logNHI (3)log(cm**-2)stat.errorfloatnullablebHI[11/37.2]? HI velocity width, fitkm/sspect.line.width;em.line.HIfloatnullablef_bHI[:] Iterative Fit flag (2)meta.codechare_bHI[0.1/1.2]? Uncertainty for bHIkm/sstat.errorfloatnullablel_[X/H]Limit flag for [X/H]meta.code.error;phys.abundchar[X/H][-3.4/0.2]? Log of the ion number abundancemeta.idfloatnullableE_[X/H][0.05/0.3]? Upper or symmetric uncertainty on [X/H] (3)stat.error;stat.maxfloatnullablee_[X/H][-0.21]? Lower uncertainty on [X/H] (3)stat.error;phys.abundfloatnullableRefs[1/3]? References for Literature Sample (4)meta.ref;pos.frameintnullableNotes[ab] Individual Object Notes (5)meta.notecharDR1Display data from the KODIAQ DR1 catalog (O'Meara+, 2015, J/AJ/150/111)meta.ref.urlintnullableDR2Display data from the KODIAQ DR2 catalog (O'Meara+, 2017, J/AJ/154/114)meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharNEDNED column added by the CDSmeta.ref.urlchar_RAPositions from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD (declination part)degpos.eq.dec;meta.mainJ/ApJ/833/283/table6Cloudy results for 21 pLLSs and LLSsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKODIAQQuasar designation (JHHMMSS+DDMMSSA)meta.id;meta.maincharzabs[2.3/3.3] Absorption redshift of LLSsrc.redshiftdoublelogNHI[16/18.7] Log HI column densitylog(cm**-2)phys.columnDensityfloatl_logNHLimit flag on logNHmeta.code.errorcharlogNH[17.3/21.5] Log total H column densityphys.columnDensityfloatl_[X/H]Limit flag on [X/H]meta.code.error;phys.abundchar[X/H][-3.4/0.2] Log of the ion number abundancemeta.idfloatl_[C/a]Limit flag on [C/a]meta.code.errorchar[C/a][-0.7/0.4]? Relative abundance of carbon to {alpha} elementsphys.abundfloatnullablel_logU[<=> ] Limit flag on logUmeta.code.errorcharlogU[-4/-1.5] Ionization parameterphys.ionizParamfloatl_NHI/NHLimit flag on NHI/NHmeta.code.errorcharNHI/NH[92.7/100] Ionization fraction%phys.atmol.ionization;arith.ratiofloatl_TLimit flag on Tmeta.code.errorcharT[0.6/3.3] Temperature10000Kphys.temperaturefloatl_lognLimit flag on lognHmeta.code.errorcharlogn[-3.3/-0.7] Log hydrogen number densitylog(cm**-3)meta.number;phys.densityfloatl_loglLimit flag on loglmeta.code.errorcharlogl[-0.5/6.3] Linear-scale of the absorberlog(pc)src.morph.scLengthfloat