J/MNRAS/440/799ivo://CDS.VizieR/J/MNRAS/440/799doi:10.26093/cds/vizier.74400799CDSVivek M.Srianand R.Petitjean P.Mohan V.Mahabal A.Samui S.2024-08-09T20:14:44Z2015-04-16T14:09:40ZCDS support team

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

cds-question@unistra.frquasarsspectroscopyWe present results of our time variability studies of MgII and AlIII absorption lines in a sample of 22 Low Ionization Broad Absorption Line QSOs (LoBAL QSOs) at 0.2<=z_em_<=2.1 using the 2-m telescope at IUCAA Girawali Observatory over a time-scale of 10d to 7.69years in the QSO's rest frame. Spectra are analysed in conjunction with photometric light curves from Catalina Real-Time Transient Survey. Long time-scale (i.e. >=1-year) absorption line variability is seen in eight cases (36 per cent systems) while only four of them (i.e. 18 per cent systems) show variability over short time-scales (i.e. <1-year). We notice a tendency of highly variable LoBAL QSOs to have high ejection velocity, low equivalent width and low redshift. The detection rate of variability in LoBAL QSOs showing Fe fine-structure lines (FeLoBAL QSOs) is less than that seen in non-Fe LoBAL QSOs. Absorption line variability is more frequently detected in QSOs having continuum dominated by Fe emission lines compared to rest of the QSOs. Confirming these trends with a bigger sample will give vital clues for understanding the physical distinction between different BAL QSO sub-classes. We correlate the absorption line variability with various parameters derived from continuum light curves and find no clear correlation between continuum flux and absorption line variabilities. However, sources with large absorption line variability also show large variability in their light curves. We also see appearance/disappearance of absorption components in two cases and clear indications for profile variations in four cases. The observed variability can be best explained by a combination of process driven by continuum variations and clouds transiting across the line of sight.2014MNRAS.440..799Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/440/799CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/698/1095 : The FIRST-2MASS red QSO survey. II. (Urrutia+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/440/799https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/440/799http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/440/799https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/440/799https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/440/799http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/440/799GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/440/799/table2 (Source parameters measured from the data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/440/799/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/440/799/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/440/799/table2?GETtext/xml+votable180.050000true11.365333314.63780560.0055555555555555566/0 5607 5627 5753 6389 6465 6510 6512 7178 8227 9796 17298 17806 19026 19760 23050 25853 26026 27335 27379 27653 36734https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/440/799?format=asciiOpticaldefaultJ/MNRAS/440/799/table2Source parameters measured from the datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSQSO SDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharNoNumber of observations (table 1)meta.numberintnullableNwNumber of equivalent widths (table 4)meta.numberintnullableSNameShort name (JHHMM+DDMM)meta.idcharprimaryn_SName[+* ] Fe emission (1)meta.notecharzem[0.5/2.0] Emission redshift (2)src.redshiftfloatzabs[0.5/2.0] Absorption redshift (3)src.redshiftfloatVmax[1865/20747] Maximum velocity (4)km/sphys.velocfloat<EW>[3/33]? Average MgII equivalent width0.1nmspect.line.eqWidth;stat.meanfloatnullablen_<EW>[a] a corresponds to average AlIII equivalent width in <EW>meta.notecharLbolBolometric luminosity (5)1e-07Wphys.luminositydoubleMbhBlack hole mass (derived from Lbol assuming Eddington accretion)solMassphys.massdoubleDm? Median variability {Delta}m valuemagsrc.var.amplitudefloatnullablee_Dm? standard deviation of Dmmagstat.errorfloatnullableSlope? Slope of {Delta}m/{Delta}t graphmag/yrstat.fit.paramfloatnullablee_Slope? rms uncertainty on Slopemag/yrstat.errorfloatnullableLineAbsorption line(s) probed in this studymeta.id;spect.linecharSloanDisplay the SDSS data for this quasarmeta.ref.urlchar_RAPositions from SDSS name (right ascension part)degpos.eq.ra;meta.main_DEPositions from SDSS name (declination part)degpos.eq.dec;meta.mainJ/MNRAS/440/799/table1Log of observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSQSO SDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharSNameShort namemeta.idcharInstObservatory/Instrument (2)meta.notecharDateObservation datetime.epoch;obsnullableMJDModified Julian datedtime.epochintExp1[5/80] Exposure time of 1 exposuremintime.duration;obs.exposureintNexpNumber of exposuresmeta.numberintlam.minLower value of wavelength coverage0.1nminstr.bandwidthintlam.maxUpper value of wavelength coverage0.1nminstr.bandwidthintResResolutionkm/sspect.resolutionintS/N[2/62] Signal-to-noise ratio (1)stat.snrintJ/MNRAS/440/799/table4Equivalent width measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNameShort namemeta.idcharn_SNameNote on componentmeta.notecharIonIonphys.atmol.ionStagecharEpochEpoch identification (1)meta.id;time.epochcharMJD? Modified Julian datedtime.epochintnullablelam.minLower value of wavelength range0.1nminstr.bandwidthfloatlam.maxUpper value of wavelength range0.1nminstr.bandwidthfloatWrestRest-frame equivalent width0.1nmspect.line.eqWidthfloate_Wrestrms uncertainty on Wrest0.1nmstat.errorfloatComment"Variable"meta.notechar