J/ApJ/818/113ivo://CDS.VizieR/J/ApJ/818/113doi:10.26093/cds/vizier.18180113CDSNeeleman M.Prochaska J.X.Ribaudo J.Lehner N.Howk J.C.Rafelski M.,Kanekar N.2022-10-05T07:44:20Z2016-05-27T12:22:12ZCDS support team

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

cds-question@unistra.frquasarsredshiftedspectroscopyultraviolet-astronomyWe use the Hubble Space Telescope (HST) archive of ultraviolet (UV) quasar spectroscopy to conduct the first blind survey for damped Ly{alpha} absorbers (DLAs) at low redshift (z<1.6). Our statistical sample includes 463 quasars with spectral coverage spanning a total redshift path {Delta}z=123.3 or an absorption path {Delta}X=229.7. Within this survey path, we identify 4 DLAs defined as absorbers with HI column density N_HI_>=10^20.3^/cm2, which implies an incidence per absorption length lDLA(X)=0.017_-0.008_^+0.014^ at a median survey path redshift of z=0.623. While our estimate of l_DLA_(X) is lower than earlier estimates at z~0 from HI 21cm emission studies, the results are consistent within the measurement uncertainties. Our data set is too small to properly sample the N_HI_ frequency distribution function f(N_HI_,X), but the observed distribution agrees with previous estimates at z>2. Adopting the z>2 shape of f(N_HI_, X), we infer an HI mass density at z~0.6 of {rho}_HI_^DLA^=0.25_-0.12_^+0.20^. This is significantly lower than previous estimates from targeted DLA surveys with the HST, but consistent with results from low-z HI 21cm observations, and suggests that the neutral gas density of the universe has been decreasing over the past 10Gyr.2016ApJ...818..113Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/818/113CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/MNRAS/452/217 : HI cosmological mass density at z=5 (Crighton+, 2015)J/ApJ/779/161 : MgII absorbers in 0.4<z<2.3 SDSS QSOs (Seyffert+, 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/736/42 : HST QSO Catalog (Ribaudo+, 2011)J/A+A/505/1087 : DLAs in SDSS-DR7 (Noterdaeme+, 2009)J/ApJ/636/610 : Damped Ly{alpha} systems at z<1.65 (Rao+, 2006)J/ApJ/635/123 : The SDSS-DR3 damped Ly{alpha} survey (Prochaska+, 2005)J/MNRAS/354/L31 : SDSS DR2 QSO and DLA properties (Murphy+, 2004)J/ApJS/140/143 : HST FOS spectral atlas (Bechtold+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/818/113https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/818/113http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/818/113https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/818/113https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/818/113http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/818/113GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/818/113/table1 (QSO sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/818/113/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/818/113/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/818/113/table1?GETtext/xml+votable180.050000true0.101667-12.7632780.0055555555555555566/0 2 134 513 532 552 1546 1701 2052 2257 2324 2397 2409 2414 2441 2621 2663 2716 2754 4107 4193 4204 4256 4269 4285 4301 4322 4333 4341 4410 4436 4448 4473 4506 4590 4594 4693 4695 4820-4821 4824 4886 4946 4955 4959 4961 4966 5061 5091 5121 5207 5213 5215 5244 5262 5264 5271 5274 5284 5290 5304-5306 5312 5345 5355 5371 5409 5413 5423 5437 5439 5452 5472 5481 5529 5570 5576 5597 5639 5657 5687 5693 5696 5722-5723 5731 5759 5767 5773 5780 5806 5818 5820-5821 5825 5860-5861 5946 5952 5959 5974 6021 6038 6054 6062 6081 6087 6104 6111 6117 6223 6238 6252 6264 6488 6536 6557 6559 6565 6576 6606 6618 6643-6644 6652 7176 7182 7190 7242 7253-7254 7277 7307 7314 7320 7381 7424 7426-7427 7448 7451 7456 7458-7460 7485 7488 7500 7508 7604 7618 7642 7725 7777 7859 7896 7902-7903 7964 7998 8017 8071 8117 8192 8196 8216 8245-8246 8266 8282 8300 8303 8469 8523 8528 8612 8638 8641 8683 8700 8702 8755 8758 8812 8838 8845 8858 8867 8906 8910 8915 8918 8922-8923 8927 8938-8939 8941 8952 9018 9031 9111 9114 9175 9181 9186 9194 9241 9252 9262 9272 9305 9330 9402 9440 9442 9455 9457 9459 9463 9471 9510 9604 9632-9633 9696 9705 9707 9753 9756 9761 9783 9817 9855 9943 9955 9959 10061 10084 10087 10092 10098 10162-10163 10170 10177 10180 10182 10187-10188 10192 10195 10212 10214 10217 10219 10261 10265 10287 10289 10297-10298 10300 10306 10315 10325 10337 10353 10379 10385 10388 10394 10408 10411 10414 10432-10433 10468 10472-10473 10495 10501 10517 10528 10571 10578 10602 10634 10659 10689 10691 10694 10709 10753 10764 10769 10807 10878 10889 10927 10940 10968-10969 10976 10995 11014 11021 11032 11040 11086 11104 11150 11203 11206 11209 11217 11260 11327 11347 11354 11378 11382 11388 11393 11396 11435 11456 11462 11473 11475 11490 11502 11504 11529-11530 11557 11560 11596-11597 11610-11611 11643 11658 11668 11686 11691 11723 11725 11750 11777 11782 11813 11829 11845 11898 11924 12025 12033 12038 12047 12317 12380 12604 12740 12752 12886 13414 13496 14520 15247 15300 15351 16080 16093 16269 16298 16301 16405 16434 16447 16652 16705 16712 16717 16765 16784 16891 16894 16897 17075 17186 17190 17203 17251 17488 17499 17575 17614 17639 17662 17673 17702-17703 17723 17730 17757 17772 17805 17816 17818-17819 17825 17827 17833 17835 17839-17840 17898 17990 17999 18001-18002 18005 18010 18027 18034 18041-18042 18060 18081 18096 18098 18105 18125 18127 18177 18207-18208 18387 18404 18506 18601 18661 18669 18756 18767 18769-18770 18772 18777 18790-18791 18802 18912 18947 19190 19283 19287 19315 19398 19416 19433 19460 19483 19510 19567 19609 19700 19712 19730 19746 19783 19807 19848 19883 19895 19932 20008 20099 20302 21126 21134 21180 21270 21991 22452 22578 22593 22658-22659 22754 23016 23045 23060 23121 23203 23210 23304 23397 24666 24687 24695 24775 24859 24974 25120 25132 25190 25245 25285 25302 25392 25472 25561 25742 25932 25935 25940 25956 25960 25964 25978 26000 26017 26019-26021 26024 26028 26033 26058 26065 26088 26100 26115 26125 26131 26192 26196 26212 26228 26238 26245 26253 26255 26259 26261 26266-26267 26270 26288 26292 26303 26334 26349 26396 26405 26407 26454 26499 26509 26525 26606 26615 26707 26755 26859 26878-26879 26888 26902 26946 26960 26965-26966 26976 26988 26996 27006 27015 27023 27025 27029-27031 27034 27037 27044 27047 27050-27051 27079 27084 27090 27096 27115 27127 27155 27160 27206 27213 27215 27226 27229 27234 27238 27248 27250 27338 27349-27350 27376 27423 27435 27486 27502 27509 27513-27516 27518 27526 27562 27580-27581 27646 27649 27653 27715 27720 27722-27723 27725 27727-27728 27731 27733 27739 27745 27751 27755-27756 27758 27760 27762 27766 27804 27807 27826 27862 27889 27909 27963-27964 28033-28034 28043 28060 28086 28143 28148 28158 28167 28180 28201 28216 28232 28315 28356 28383 28395 28401 28419 28468 28471 28479 28527 28532 28535 28540 28546 28564 28571 28589 28611 28636 28648 28666 29162 29398 30010 31211 31382 31386 31397 31404-31405 31422 31535 31650 31658 31663 31686 31857 32344 32948 32986 32998 33126 33233 33561 33620 33623 33684 33796 33827 33930 33950 33968 34035 34065 34123 34202 34210 34233 34291 34299 34321 34330 34534 34652 34669 34672 34770 34777 34881 35018 35180 35205 35272 35360 35496 35542 35559 35576 35607 35647 35741 35749 35769 35801 35833 35893 35897 35987 35992-35993 35995 36086 36101 36139 36178 36260 36313 36443 36495 36648 36775 36786 36788 36802 36862 37385 37474 38205 38268 38383 38853 38916 40479 40730 40809 42666 43417 43680 43870 43900 43922 43957 44028 44043 44310 44387 44587 44785 44938 44988 45341 45409 45500 45517 45526 45621 46159 46165 46229 46279 46281 46299 46418 46527 46577 46647 46729 46753 46795 46964 47001 47014 47169 47375 48406 48420 48470 48502 48594 48614 48965 49042https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/818/113?format=asciiUVdefaultJ/ApJ/818/113/table1QSO sampleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOQSO identifier (JHHMM+DDMM)meta.id;meta.maincharAltQSOAlternate QSO identifiermeta.idcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainzem[0/4.7] Emission redshift of the QSOsrc.redshiftfloatInstInstrument used ("COS", "FOS", "STIS")instr.setupcharGrateGrating usedinstr.setupcharFSrch? Flag for search path (1)meta.codeintnullablezShmin[0.01/1.7]? Minimum Redshift of Search Pathstat.fit.paramfloatnullablezShmax[0.09/1.7]? Maximum Redshift of Search Pathstat.fit.paramfloatnullableFStat? Flag for statistical path (2)meta.codeintnullablezStmin[0.01/1.7]? Minimum Redshift of Statistical Pathstat.fit.paramfloatnullablezStmax[0.01/1.7]? Maximum Redshift of Statistical Pathstat.fit.paramfloatnullablePropProposal Identification Numbermeta.id;obschar