J/MNRAS/449/1536ivo://CDS.VizieR/J/MNRAS/449/1536doi:10.26093/cds/vizier.74491536CDSTurnshek D.A.Monier E.M.Rao S.M.Hamilton T.S.Sardane G.M.Held R.2024-08-14T20:20:47Z2016-01-06T15:17:50ZCDS support team

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

cds-question@unistra.frquasarsredshiftedline-intensitiesQuasar damped Ly{alpha} (DLA) absorption-line systems with redshifts z<1.65 are used to trace neutral gas over approximately 70 percent of the most recent history of the Universe. However, such systems fall in the UV and are rarely found in blind UV spectroscopic surveys. Therefore, it has been difficult to compile a moderate-sized sample of UV DLAs in any narrow cosmic time interval. However, DLAs are easy to identify in low-resolution spectra because they have large absorption rest equivalent widths. We have performed an efficient strong-Mg ii-selected survey for UV DLAs at redshifts z=[0.42,0.70] using Hubble Space Telescope's low-resolution ACS-HRC-PR200L prism. This redshift interval covers ~1.8Gyr in cosmic time, i.e. t~[7.2,9.0]Gyr after the big bang. A total of 96 strong MgII absorption-line systems identified in Sloan Digital Sky Survey spectra were successfully observed with the prism at the predicted UV wavelengths of Ly{alpha} absorption. We found that 35 of the 96 systems had a significant probability of being DLAs. One additional observed system could be a very high N_HI_ DLA (N_HI_~2x10^22^atoms/cm^2^ or possibly higher), but since very high N_HI_ systems are extremely rare, it would be unusual for this system to be a DLA given the size of our sample. Here we present information on our prism sample, including our best estimates of N_HI_ and errors for the 36 systems fitted with DLA profiles. This list is valuable for future follow-up studies of low-redshift DLAs in a small redshift interval, although such work would clearly benefit from improved UV spectroscopy to more accurately determine their neutral hydrogen column densities.2015MNRAS.449.1536Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/449/1536CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/636/610 : Damped Ly{alpha} systems at z<1.65 (Rao+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/449/1536https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/449/1536http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/449/1536https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/449/1536https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/449/1536http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/449/1536GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/449/1536/table1 (The observed prism sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/449/1536/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/449/1536/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/449/1536/table1?GETtext/xml+votable180.050000true4.730125-9.23086110.0055555555555555566/546 4112 4163 4793 4849 5034 5047 5485 5706 5765 5801 5979 5985 6023 6033 6121 6130 6224 6352 6355 6441 6447 6465 6498 6562 6565 6622 6644 7198 7435 7455 7458 7471 7514 7529 7538 8212 9076 9608 9646 9773 9825 9911 9914 9957 9992 10114 10563 10631 10966 11036 11058 11069 11160 11178 11184 11195 11199 11209 11266 11290 11350 11372 11437 11453 11455 11474 11782 11796 11812 11826 11837 11840 11850 11854 11905 12390 12409 17253 17601 17665-17666 18772 18790 19390 20032 25845 25924 25994 26049 26091 26408 26995 27228 27314 27323 27357 27527 27553 27671 27736 27755 27818 30037 31686 32430 36726 367303.588997330618193e-19 4.653515163505597e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/449/1536?format=asciiOpticaldefaultJ/MNRAS/449/1536/table1The observed prism sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOQSO name (JHHMMSS.ss+DDMMSS.s or HHMM+DDMMCAL)meta.id;meta.maincharprimaryExpTime? Exposure timestime.duration;obs.exposureintnullablegmag? SDSS g magnitudemagphot.mag;em.opt.Bfloatnullablen_gmag[*] Note on gmagmeta.notecharzem? Emission redshiftsrc.redshiftfloatnullablezabsAbsorption redshiftsrc.redshiftfloatW0(2796)MgII (2796{AA}) rest equivalent width0.1nmspect.line.widthfloate_W0(2796)rms uncertainty on W0(2796)0.1nmstat.errorfloatW0(2803)MgII (2803{AA}) rest equivalent width0.1nmspect.line.widthfloate_W0(2803)rms uncertainty on W0(2803)0.1nmstat.errorfloatW0(2852)MgI (2852{AA}) rest equivalent width0.1nmspect.line.widthfloate_W0(2852)rms uncertainty on W0(2852)0.1nmstat.errorfloatW0(2600)? FeII (2600{AA}) rest equivalent width0.1nmspect.line.widthfloatnullablee_W0(2600)? rms uncertainty on W0(2600)0.1nmstat.errorfloatnullableStatus[ABCDE] Status (1)meta.codecharNHIindicates NHI data in table2meta.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.mainJ/MNRAS/449/1536/table2Column density measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSOQSO name (JHHMMSS.ss+DDMMSS.s or HHMM+DDMMCAL)meta.id;meta.maincharzabsAbsorption redshift from MgII linesrc.redshiftfloatl_NHI[>= ] Limit flag on NHImeta.code.errorcharNHIHI column densitycm**-2phys.columnDensitydoublee_NHI? rms uncertainty on NHIcm**-2stat.errordoublenullableNotes[abcdef] Notes (1)meta.notechar