J/ApJ/800/7ivo://CDS.VizieR/J/ApJ/800/7doi:10.26093/cds/vizier.18000007CDSNeeleman M.Prochaska J.X.Wolfe A.M.2017-07-03T14:25:32Z2015-07-28T07:27:01ZCDS support team

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

cds-question@unistra.frquasarsredshiftedchemical-abundancesspectroscopyinterstellar-mediumA new method is used to measure the physical conditions of the gas in damped Ly{alpha} systems (DLAs). Using high-resolution absorption spectra of a sample of 80 DLAs, we are able to measure the ratio of the upper and lower fine-structure levels of the ground state of C^+^ and Si^+^. These ratios are determined solely by the physical conditions of the gas. We explore the allowed physical parameter space using a Monte Carlo Markov chain method to constrain simultaneously the temperature, neutral hydrogen density, and electron density of each DLA. The results indicate that at least 5% of all DLAs have the bulk of their gas in a dense, cold phase with typical densities of ~100/cm3 and temperatures below 500K. We further find that the typical pressure of DLAs in our sample is log(P/k_B_)=3.4(K/cm3), which is comparable to the pressure of the local interstellar medium (ISM), and that the components containing the bulk of the neutral gas can be quite small with absorption sizes as small as a few parsecs. We show that the majority of the systems are consistent with having densities significantly higher than expected for a purely canonical warm neutral medium, indicating that significant quantities of dense gas (i.e., n_H_>0.1/cm3) are required to match observations. Finally, we identify eight systems with positive detections of Si II*. These systems have pressures (P/k_B_) in excess of 20000K/cm3, which suggest that these systems tag a highly turbulent ISM in young, star-forming galaxies.2015ApJ...800....7Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/800/7CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/MNRAS/435/482 : DLA system from SDSS DR5 (Jorgenson+, 2013)J/ApJ/769/54 : Spectroscopy of DLA systems (Neeleman+, 2013)J/ApJ/755/89 : Metallicities of damped Ly{alpha} systems (Rafelski+, 2012)J/ApJS/171/29 : UCSD/Keck DLA Abundance Database (Prochaska+, 2007)J/ApJ/649/L61 : SDSS J155810.16-003120.0 abundances (O'Meara+, 2006)J/PASP/118/1077 : Metal-strong damped Ly{alpha} systems (Herbert-Fort+, 2006)J/ApJ/635/123 : The SDSS-DR3 damped Ly{alpha} survey (Prochaska+, 2005)J/ApJS/145/329 : Millennium Arecibo 21-cm Survey (Heiles+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/800/7https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/800/7http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/800/7https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/800/7https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/800/7http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/800/7GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/800/7/dla (Fine structure damped Ly{alpha} sample and results of SiII* and CII* technique)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/800/7/dla?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/800/7/dla?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/800/7/dla?GETtext/xml+votable180.050000true179.93677891.20195670.0055555555555555566/523 2172 4168 4273 4481 4608 4623 4946 4947 5061 5234 5270 5333 5723 6042 6106 6403 6425 6591 6644 7168 8303 8305 8343 8515 9095 9730 9968 10103 10602 10742 10939 11092 11113 11418 11765 16831 17190 17257 17317 17404 17778 17895 18112 18765 19408 19680 19682 20016 22917 23099 25986 26166 26429 26479 26533 26553 26586 26981 27423 27437 27485 27508 27510 27650 27667 27687 27780 27943 28281 28539 28614 28669 31331 34503 44724 48474 49086 49100https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/800/7?format=asciiOpticaldefaultJ/ApJ/800/7/dlaFine structure damped Ly{alpha} sample and results of SiII* and CII* techniqueSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/80] Running sequence number of the DLAmeta.numberintprimaryQSOQSO namemeta.id;meta.maincharzabs[1.6/4.9] Absorption redshift of DLAsrc.redshiftfloatNHI[20.3/22.1] Log of the hydrogen column densitylog(cm**-2)phys.columnDensityfloate_NHI[0.05/0.2] Error in NHIlog(cm**-2)stat.errorfloat[M/H][-2.6/-0.1] Log of metal "M" to hydrogen number abundancelog(Sun)meta.idfloate_[M/H][0.05/0.5] Error in [M/H]log(Sun)stat.error;phys.abundfloatMIon used for metallicity determination (O, S, Fe, Si or Zn)phys.atmol.ionStagecharl_NCIIsLimit flag on NCIIsmeta.code.errorcharNCIIs[12.5/15.7] Log of column density of CII*log(cm**-2)phys.columnDensityfloatf_NCIIs[*] * = fitted using VPFIT (1)meta.codechare_NCIIs[0.01/0.2]? Error in NCIIslog(cm**-2)stat.errorfloatnullablel_NSiIIsLimit flag on NSiIIsmeta.code.errorcharNSiIIs[11/13.7] Log of column density of SiII*log(cm**-2)phys.columnDensityfloate_NSiIIs[0.02/0.2]? Error in NSiIIslog(cm**-2)stat.errorfloatnullablel_NSiIILimit flag on NSiIImeta.code.errorcharNSiII[13.3/16.6] Log of column density of SiIIlog(cm**-2)phys.columnDensityfloatf_NSiII[*] * = fitted using VPFIT (1)meta.codechare_NSiII[0.01/0.5]? Error in NSiIIlog(cm**-2)stat.errorfloatnullableN13[NY] Part of the sample of Neeleman et al. 2013, J/ApJ/769/54meta.codecharRefReference (2)meta.ref;pos.framecharb1NHThe 1{sigma} lower limit to log(HI density)log(cm**-3)phys.densityfloatB1NHThe 1{sigma} upper limit to log(HI density)log(cm**-3)phys.densityfloatb2NHThe 2{sigma} lower limit to log(HI density)log(cm**-3)phys.densityfloatB2NHThe 2{sigma} upper limit to log(HI density)log(cm**-3)phys.densityfloatb1NeThe 1{sigma} lower limit to log(electron density)log(cm**-3)phys.densityfloatB1NeThe 1{sigma} upper limit to log(electron density)log(cm**-3)phys.densityfloatb2NeThe 2{sigma} lower limit to log(electron density)log(cm**-3)phys.densityfloatB2NeThe 2{sigma} upper limit to log(electron density)log(cm**-3)phys.densityfloatb1TThe 1{sigma} lower limit to log(temperature)log(K)phys.temperaturefloatB1TThe 1{sigma} upper limit to log(temperature)log(K)phys.temperaturefloatb2TThe 2{sigma} lower limit to log(temperature)log(K)phys.temperaturefloatB2TThe 2{sigma} upper limit to log(temperature)log(K)phys.temperaturefloatb1P/kThe 1{sigma} lower limit to log(pressure/k_B_)log(K.cm**-3)phys.pressurefloatB1P/kThe 1{sigma} upper limit to log(pressure/k_B_)log(K.cm**-3)phys.pressurefloatb2P/kThe 2{sigma} lower limit to log(pressure/k_B_)log(K.cm**-3)phys.pressurefloatB2P/kThe 2{sigma} upper limit to log(pressure/k_B_)log(K.cm**-3)phys.pressurefloatQcatSources within 2" from the QSOs catalogs: Neeleman+, 2013, J/ApJ/769/54; Rafelski+, 2012, J/ApJ/755/89; Veron+, 2010, VII/258; Prochaska+, 2007, J/ApJS/171/29 and Herbert-Fort, 2006, J/PASP/118/1077meta.ref.urlintnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlchar_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.main