J/MNRAS/518/5590ivo://CDS.VizieR/J/MNRAS/518/5590doi:10.26093/cds/vizier/bg-g6-5epCDSFang H.Xia I.Ge J.Willis K.Zhao Y.2026-08-03T07:32:23Z2026-03-05T13:17:16ZCDS support team

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

cds-question@unistra.frquasarsgalaxiesspectroscopyultraviolet-astronomyvisible-astronomyline-intensitiesredshiftedastrometryWe report discoveries of 165 new quasar Ca II absorbers from the Sloan Digital Sky Survey (SDSS) Data Releases 7 and 12. Our CA II rest-frame equivalent width distribution supports the weak and strong subpopulations, split at W_0_^{lambda}3934^ = 0.7{AA}. Comparison of both populations' dust depletion shows clear consistency for weak absorber association with halo-type gas in the Milky Way (MW), while strong absorbers have environments consistent with halo and disc- type gas. We probed our high-redshift Ca II absorbers for 2175{AA} dust bumps, discovering 122175 {AA} dust absorbers (2DAs). This clearly shows that some Ca II absorbers follow the Large Magellanic Cloud (LMC) extinction law rather than the Small Magellanic Cloud extinction law. About 33 per cent of our strong Ca II absorbers exhibit the 2175 {AA} dust bump, while only 6 per cent of weak Ca II absorbers show this bump. 2DA detection further supports the theory that strong Ca II absorbers are associated with disc components and are dustier than the weak population. Comparing average Ca II absorber dust depletion patterns to that of Damped Ly {alpha} absorbers (DLAs), Mg II absorbers, and 2DAs shows that Ca II absorbers generally have environments with more dust than DLAs and Mg II absorbers, but less dust than 2DAs. Comparing 2175 {AA} dust bump strengths from different samples and also the MW and LMC, the bump strength appears to grow stronger as the redshift decreases, indicating dust growth and the global chemical enrichment of galaxies in the Universe over time.2023MNRAS.518.5590Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/518/5590CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/458/4074 : UVES Advanced Data Products Quasar Sample. VI.J/MNRAS/444/1747 : CaII absorbers in SDSS QSOs (Sardane+, 2014)J/A+A/528/A12 : QSOs CaII absorbers (Richter+, 2011)J/ApJ/732/110 : SDSS 2175{AA} extinction bump candidates (Jiang+, 2011)J/ApJ/663/320 : IR-through-UV extinction curve (Fitzpatrick+, 2007)J/AJ/145/157 : Reddening curve of IRAS 14026+4341 (Jiang+, 2013)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)II/294 : The SDSS Photometric Catalog, Release 7https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/518/5590https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/518/5590http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/518/5590https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/518/5590https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/518/5590http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/518/5590GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/518/5590/table2 (New quasars Ca II absorbers discovered)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/518/5590/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/518/5590/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/518/5590/table2?GETtext/xml+votable180.050000true143.247.70.0055555555555555566/4176 4265 4319 4349 4359 4369-4370 4386 4456 4565 4573 4653 4949 4970 5113 5131 5134 5261 5345 5412 5478 5492 5571-5572 5626 5638 5817 5873 6007 6066 6117 6125 6270 6593 6599 6918 7179 7210 7216 7225 7356 7379 7431 7440 7460 8282 8330 8346 8370 8476 8597 8606 8700 8753 9006 9053 9076 9105 9120 9219-9220 9436 9846 9887 9926 10307 10410 10527 10548 10571-10572 10631 10706 10719 10729 10743 10865 10906 10922 10975 11009 11143 11174 11184 11209 11290 11399 11413 11428 11434 11456 11471 11491 11524 11534 12660 17692 17702 17743 17754 17772 17840 17968 18096 18173 18298 18345 18887 19326 19629 19661 19759 19779 20109 20129 20200 22351 26005 26175 26276 26325 26423 26540 26559 26609 26878 27030 27303 27415 27478 27519 27594 27622 27700 27702 27728 27755 27763 27841 28116 28141 28202 28387 28399 28403 28506 28515 31357 31622 31628https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/518/5590?format=asciiUVOpticaldefaultJ/MNRAS/518/5590/table2New quasars Ca II absorbers discoveredrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexIndex raw number (index)meta.idintQuasarQuasar name designation as JHHMMSS.ss+DDMMSS.s (Quasar)meta.id;meta.maincharRAJ2000Right ascension (J2000) (ra)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (dec)degpos.eq.dec;meta.mainzemRedshift of the emission (z_em_)src.redshiftfloatzabsRedshift of the absorption (z_abs)src.redshiftfloatW03934Ca II rest-frame equivalent width at 3934{AA} (W_0_^{lambda}3934^)0.1nmspect.line.eqWidthfloate_W03934Error of W03934 (errW_0_^{lambda}3934^)0.1nmstat.errorfloatW03969Ca II rest-frame equivalent width at 3969{AA} (W_0_^{lambda}3969^)0.1nmspect.line.eqWidthfloate_W03969Error of W03969 (errW_0_^{lambda}3969^)0.1nmstat.errorfloatSDSS-DR7Display the SDSS DR7 cataloguemeta.numberintnullableSDSS-DR12Display the SDSS DR12 cataloguemeta.numberintnullableSardane+14Display the CaII absorbers in SDSS QSOs catalogue of Sardane et al. (2014MNRAS.444.1747S, Cat. J/MNRAS/444/1747)meta.numberintnullableSloan12Display the online SDSS-DR12 data for the nearest objectmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullable