J/ApJS/242/28ivo://CDS.VizieR/J/ApJS/242/28doi:10.26093/cds/vizier.22420028CDSYi W.Brandt W.N.Hall P.B.Vivek M.Grier C.J.Ak N.F.,Schneider D.P.McGraw S.M.2020-04-20T13:45:10Z2020-01-31T15:18:22ZCDS support team

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

cds-question@unistra.frquasarsvisible-astronomyspectroscopyredshiftedline-intensitiesWe present absorption variability results for 134 bona fide MgII broad absorption-line (BAL) quasars at 0.46<=z<=2.3 covering days to ~10yr in the rest frame. We use multiple-epoch spectra from the Sloan Digital Sky Survey, which has delivered the largest such BAL variability sample ever studied. MgII-BAL identifications and related measurements are compiled and presented in a catalog. We find a remarkable time-dependent asymmetry in the equivalent width (EW) variation from the sample, such that weakening troughs outnumber strengthening troughs, the first report of such a phenomenon in BAL variability. Our investigations of the sample further reveal that (i) the frequency of BAL variability is significantly lower (typically by a factor of 2) than that in high-ionization BALQSO samples, (ii) MgII-BAL absorbers tend to have relatively high optical depths and small covering factors along our line of sight, (iii) there is no significant EW-variability correlation between MgII troughs at different velocities in the same quasar, and (iv) the EW-variability correlation between MgII and AlIII BALs is significantly stronger than that between MgII and CIV BALs at the same velocities. These observational results can be explained by a combined transverse-motion/ionization-change scenario, where transverse motions likely dominate the strengthening BALs while ionization changes and/or other mechanisms dominate the weakening BALs.2019ApJS..242...28Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/242/28CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)J/AJ/106/848 : QSO MgII absorption line systems (Drinkwater+, 1993)J/ApJS/165/1 : BAL QSOs from SDSS DR3 (Trump+, 2006)J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJ/748/131 : MgII absorbers in SDSS-DR7 quasar catalog (Shen+, 2012)J/ApJ/777/168 : CIV and SiIV BAL troughs in SDSS (Filiz+, 2013)J/ApJ/779/161 : MgII absorbers in 0.4<z<2.3 SDSS QSOs (Seyffert+, 2013)J/ApJ/791/88 : C IV BAL troughs properties in quasars (Filiz+, 2014)J/MNRAS/440/799 : Low Ionization BALQSOs MgII & AlIII var. (Vivek+, 2014)J/ApJ/814/150 : Variability of SDSS broad absorption line QSOs (Wang+, 2015)J/ApJ/824/130 : SDSS/BOSS/TDSS CIV BAL quasars (Grier+, 2016)J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)J/MNRAS/463/2640 : SDSS-DR12 QSOs MgII absorption systems (Raghunathan+, 2016)J/ApJS/235/11 : Absorption features in SDSS. I. MgII doublets (Chen+, 2018)J/A+A/616/A114 : CIV BAL disappearance in SDSS QSOs (De Cicco+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/242/28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/242/28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/242/28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/242/28https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/242/28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/242/28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/242/28/table2 (Properties of MgII-BAL QSOs in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/242/28/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/242/28/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/242/28/table2?GETtext/xml+votable180.050000true15.96858330.62769440.005555555555555556Cone search capability for table J/ApJS/242/28/table3 (MgII-BAL trough identifications and quantitative measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/242/28/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/242/28/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/242/28/table3?GETtext/xml+votable180.050000true15.968640.627720.0055555555555555566/4175 4178 4208 4369 4769 4832 4895 4932 5313 5333 5338 5341 5357 5360 5397 5456 5498 5559 5613 5617 5882 5971 6229 6443 6509 6515 6579 6618 7168 7173 7257 7262 7272 7292 7341 7352 7443 7450 7489 7556 7681 7684 8346 8826 9170 9308 9324 9391 9408 9434 9435 9472 9741 9747 9811 9868 9882 9918 9998 10093 10349 10385 10593 10618 10633 10722 10839 10845 10896 11044 11058 11062 11247 11326 11329 11335 11406 11432 11464 11474 11797 11913 11938 17298 17516 17661 17663 17750 17753 17766 17773 17811 17817 18023 18772 18787 18792 18851 19026 19389 19429 19663 23203 23205 25851 26002 26014 26331 26379 26554 26592 26951 26967 26988 26989 27094 27310 27379 27433 27446 27453 27459 27732 27760 27766 27782 27847 27919 27963 28179 28590 31399 32429https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/242/28?format=asciiOpticaldefaultJ/ApJS/242/28/table2Properties of MgII-BAL QSOs in the samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNmNumber of measurements for this QSO (link to Table 3)meta.numberintnullableSDSSSDSS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharprimaryz[0.4/2.3] Spectroscopic redshiftsrc.redshiftfloatNe[2/47] Number of epochsmeta.numberintRL[1/897]? Radio loudness from Shen+, 2011, J/ApJS/194/45phot.flux;arith.ratiofloatnullableiMag[-28.4/-22.9] Absolute i band magnitude from Schneider+ 2010, VII/260magphys.magAbsfloatS11Display data from Shen+, 2011, J/ApJS/194/45meta.ref.urlcharSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharNEDNED column added by the CDSmeta.ref.urlchar_RAPositions from SDSS names (right ascension part)degpos.eq.ra;meta.main_DEPositions from SDSS names (declination part)degpos.eq.dec;meta.mainJ/ApJS/242/28/table3MgII-BAL trough identifications and quantitative measurementschi2[0.4/60.4] Model {chi}^2^stat.param;meta.modelledfloatd2[-0.05/0.9] BAL depth at MJD2phot.flux.density;arith.ratiofloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000[15.9/360] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-11/65.1] Declination (J2000)degpos.eq.dec;meta.mainMJD1[51614/57460] First Modified Julian Datedtime.epochintMJD2[51936/58230] Second Modified Julian Datedtime.epochintNv[0/9] Number of variable regions in the trough pairmeta.id;obs.fieldintVmax[-25956/-1390] Maximum limits of trough velocitykm/sspect.dopplerVeloc;stat.maxintVmin[-24111/1269] Minimum limits of trough velocitykm/sspect.dopplerVeloc;stat.minintd1[-0.2/0.9] BAL depth at MJD1phot.flux.density;arith.ratiofloatEW1[0.5/110.4] First equivalent width; in Angstroms0.1nmspect.line.eqWidthfloate_EW1[0.04/4.3] Uncertainty in EW10.1nmstat.errorfloatEW2[0.1/112.3] Second equivalent width; in Angstroms0.1nmspect.line.eqWidthfloate_EW2[0.03/4.3] Uncertainty in EW20.1nmstat.errorfloat