J/ApJ/777/168ivo://CDS.VizieR/J/ApJ/777/168doi:10.26093/cds/vizier.17770168CDSFiliz Ak N.Brandt W.N.Hall P.B.Schneider D.P.Anderson S.F.,Hamann F.Lundgren B.F.Myers A.D.Paris I.Petitjean P.Ross N.P.,Shen Y.York D.2021-08-10T12:14:44Z2015-05-15T10:06:41ZCDS support team

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

cds-question@unistra.frquasarsredshiftedline-intensitiesspectroscopyWe present a detailed investigation of the variability of 428 CIV and 235 SiIV broad absorption line (BAL) troughs identified in multi-epoch observations of 291 quasars by the Sloan Digital Sky Survey-I/II/III. These observations primarily sample rest-frame timescales of 1-3.7yr over which significant rearrangement of the BAL wind is expected. We derive a number of observational results on, e.g., the frequency of BAL variability, the velocity range over which BAL variability occurs, the primary observed form of BAL-trough variability, the dependence of BAL variability upon timescale, the frequency of BAL strengthening versus weakening, correlations between BAL variability and BAL-trough profiles, relations between CIV and SiIV BAL variability, coordinated multi-trough variability, and BAL variations as a function of quasar properties. We assess implications of these observational results for quasar winds. Our results support models where most BAL absorption is formed within an order-of-magnitude of the wind-launching radius, although a significant minority of BAL troughs may arise on larger scales. We estimate an average lifetime for a BAL trough along our line-of-sight of a few thousand years. BAL disappearance and emergence events appear to be extremes of general BAL variability, rather than being qualitatively distinct phenomena. We derive the parameters of a random-walk model for BAL EW variability, finding that this model can acceptably describe some key aspects of EW variability. The coordinated trough variability of BAL quasars with multiple troughs suggests that changes in "shielding gas" may play a significant role in driving general BAL variability.2013ApJ...777..168Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/777/168CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/252 : SDSS-DR5 quasar catalog (Schneider+, 2007)II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/ApJS/215/12 : BOSS narrow CIV absorption lines. II. zem>2.4 (Chen+, 2014)J/ApJS/210/7 : BOSS narrow CIV absorption lines. I. zem<=2.4 (Chen+, 2014)J/ApJ/763/37 : SDSS QSO metals. I. 1.5<z<4.5 CIV absorbers (Cooksey+, 2013)J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJ/729/87 : SiIV absorption systems (Cooksey+, 2011)J/MNRAS/410/860 : Redshift dependence of BAL QSOs (Allen+, 2011)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/MNRAS/399/2231 : SDSS DR5 BALQSO catalog (Scaringi+, 2009)J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)J/ApJ/665/990 : SDSS DR2 BAL QSOs (Ganguly+, 2007)J/ApJ/641/78 : CIV variability in 105 SDSS quasars (Wilhite+, 2006)J/ApJS/165/1 : BAL QSOs from SDSS DR3 (Trump+, 2006)J/AJ/125/1711 : Broad Absorption Line Quasars from SDSS (Reichard+, 2003)http://www.sdss.org/ : SDSS home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/777/168https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/777/168http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/777/168https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/777/168https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/777/168http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/777/168GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/777/168/qsos (List of QSOs (table added by CDS))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/777/168/qsos?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/777/168/qsos?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/777/168/qsos?GETtext/xml+votable180.050000true3.75941670.20344440.005555555555555556Cone search capability for table J/ApJ/777/168/troughs (CIV- (table2) and SiIV- (table3) BAL troughs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/777/168/troughs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/777/168/troughs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/777/168/troughs?GETtext/xml+votable180.050000true3.759430.203460.0055555555555555566/552 4124 4134 4139 4192 4210 4224 4234 4240 4242 4361 4362 4665 4727 4743 4803 4813 4831 4833 5018 5055 5080 5082 5084 5327 5332 5354 5395 5396 5397 5437 5449 5458 5515 5517 5527 5530 5539 5569 5654 5676 5683 5698 5714 5761 5766 5779 5798 5863 5878 6237 6247 6267 6337 6388 6419 6435 6477 6479 6487 6502 6503 6513 6517 6559 6599 6606 6607 6640 7316 7424 7460 7480 8192 8228 8234 8321 8374 8375 8376 8719 8831 9054 9143 9161 9170 9176 9181 9201 9211 9234 9256 9290 9324 9331 9357 9359 9374 9385 9396 9399 9403 9406 9413 9416 9440 9457 9464 9514 9519 9632 9636 9646 9733 9753 9769 9789 9791 9797 9806 9849 9851 9900 9901 9914 9989 10362 10510 10519 10531 10544 10551 10559 10571 10607 10611 10641 10649 10658 10698 10795 10812 10850 10882 11265 17665 17668 17727 17754 17755 17756 17757 17764 17766 17776 17816 17821 17830 17857 18026 18028 18032 18069 18076 18086 18113 18302 18416 18772 18776 18857 18865 19025 19030 19094 21849 21852 21972 21998 25911 25939 25943 25959 25969 25976 26006 26007 26010 26016 26019 26058 26105 26106 26193 26206 26212 26217 26228 26235 26236 26239 26258 26276 26305 26328 26368 26373 26405 26407 26411 26481 26490 26497 26986 27025 27035 27046 27052 27059 27069 27078 27129 27133 27197 27198 27260 27303 27319 27345 27360 27380 27427 27430 27444 27520 27571 27573 27593 27605 27652 27659 27666 27686 27687 27697 27706 27708 27714 27748 27750 27787 27795 27796 27821 27875 27886 27896 27918 27941 27942 28160 28171 28180 28204 28210 28537 28605 28607 28615 28636 28637 28644 28658 31385 31395 31399 31473 31625 31633 32442 32480 32497 36778 45046https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/777/168?format=asciidefaultJ/ApJ/777/168/qsosList of QSOs (table added by CDS)zReshiftsrc.redshift;pos.heliocentriccharNcNumber of CIV BAL troughs for this quasarmeta.numbercharNsNumber of SiIV BAL troughs for this quasarmeta.numbercharNcvNumber of CIV BAL-trough variable regions for this quasarmeta.numbercharNsvNumber of SiIV BAL trough variable regions for this quasarmeta.numbercharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSQSO identification; JHHMMSS.ss+DDMMSS.smeta.id;meta.maincharprimaryCCatSources within 2" from Chen et al. 2014, J/ApJS/210/7 and J/ApJS/215/12meta.ref.urlintnullableDRQDisplay the SDSS-DR10, -DR9 and -DR7 quasar data (VII/270, VII/269 and VII/260) for this QSOmeta.ref.urlcharDR9Display the SDSS-DR9 photometric catalog (V/139) within 1"meta.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/ApJ/777/168/troughsCIV- (table2) and SiIV- (table3) BAL troughse_d2[0/1] Error in d2stat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBIDBAL trough identifier (G1)meta.id;meta.maincharSDSSQSO identification; JHHMMSS.ss+DDMMSS.smeta.id.assoccharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainz[2/4] Redshiftsrc.redshiftfloate_z[0.0002/0.003] Error in zstat.error;src.redshiftdoubleL[0/1] 1=LoBAL (low ionization BAL) flagmeta.codeintT[0/1] 1=timescale>1yr (2)meta.codeintPlate1First-epoch spectrum plate numbermeta.id;instr.plateintMJD1First-epoch Modified Julian observation Datedtime.epochintFib1First-epoch spectrum fiber numbermeta.noteintSN1[10/40] Signal-to-noise at 1700{AA} for the first-epoch spectrumstat.snrfloatPlate2Second-epoch spectrum plate numbermeta.id;instr.plateintMJD2Second-epoch Modified Julian observation Datedtime.epochintFib2Second-epoch spectrum fiber numbermeta.noteintSN2[10/60] Signal-to-noise at 1700{AA} for the second-epoch spectrumstat.snrfloatdt[0.2/1353] Rest-frame timescale between the two observationsdtime.intervaldoubleVmax[-30000/-5074] Maximum (blue-edge) velocity of BAL troughkm/sspect.dopplerVelocfloatVmin[-27395/-3000] Minimum (red-edge) velocity of BAL troughkm/sspect.dopplerVelocfloatVc1[-28841/-4074] First-epoch centroid velocity of the BAL troughkm/sspect.dopplerVelocfloatVc2[-28725/-4166] Second-epoch centroid velocity of the BAL troughkm/sspect.dopplerVelocfloatd1[-0.03/1] First-epoch average BAL trough depthphot.flux.density;arith.ratiofloate_d1[0/1] Error in d1stat.errorfloatd2[0/1] Second-epoch average BAL trough depthphot.flux.density;arith.ratiofloatEW1First-epoch CIV/SiIV equivalent width ({AA})0.1nmspect.line.eqWidthfloate_EW1Error in EW10.1nmstat.errorfloatEW2Second-epoch CIV/SiIV equivalent width ({AA})0.1nmspect.line.eqWidthfloate_EW2Error in EW20.1nmstat.errorfloatDEWEquivalent width variation {Delta}EW=EW2-EW10.1nmarith.rate;spect.line.eqWidthe_DEWError in DEW0.1nmstat.errorfloatfEW[-2/2] Fractional equivalent width variation {Delta}EW/<EW> = 2(EW2-EW1)/(EW2+EW1)arith.rate;spect.line.eqWidth;arith.ratiofloate_fEWError in fEWstat.errorfloatNv[0/14] Number of variable regions detected in BAL troughmeta.numberintSum[0/10960] Total width of the variable regionskm/sspect.line.widthfloatfDV[0/1] Ratio f_{Delta}V_ of total variable region width and the BAL trough widthspect.line.intensity;arith.ratiofloatxBALCorresponding SiIV/CIV BAL Trough IDs as given in Table 3 or Table 2 (3)meta.id.assoccharnullablelogLbLog of Quasar bolometric luminosity (erg/s)log(1e-07W)phys.luminosityfloate_logLbError in logLblog(1e-07W)stat.errorfloatlogM? Log of black-hole masslog(solMass)phys.massfloatnullablee_logM? Error in logMlog(solMass)stat.errorfloatnullablelogLe[-1.7/0.8]? log of luminosity to i Eddington luminosity ratiophys.luminosity;arith.ratiodoublenullableiMag[-29.8/-26.7] Absolute i-band magnitudemagphys.magAbsfloatR[1/598]? Radio-loudness parameter (R=F_6cm_/F_2500{AA}_)phot.flux;arith.ratiofloatnullableSp1Interactive spectrum from SDSS for the first epochmeta.ref.urlcharSp2Interactive spectrum from SDSS for the second epochmeta.ref.urlcharJ/ApJ/777/168/varegsCIV- (table4) and SiIV- (table5) BAL-trough variable regionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVIDVariable region identifier (G1)meta.id;meta.maincharSDSSQSO identification; JHHMMSS.ss+DDMMSS.smeta.id.assoccharMJD1Modified Julian date of first-epoch observationdtime.epochintMJD2Modified Julian date of second-epoch observationdtime.epochintBIDCIV BAL/SiIV BAL trough ID as given in Table 2/Table 3meta.id.assoccharVb.max[-30000/-5074] Maximum (blue-edge) velocity of BAL troughkm/sspect.line.widthfloatVb.min[-27395/-3000] Minimum (red-edge) velocity of BAL troughkm/sspect.line.widthfloatVv.max[-29977/-3321] Maximum (blue-edge) velocity of variable regionkm/sspect.line.widthdoubleVv.min[-29531/-3018] Minimum (red-edge) velocity of variable regionkm/sspect.line.widthdoubledVr[273/7861] Width of variable regionkm/sspect.line.width;obs.fieldfloatVnrt[-1.5/1.2] Normalized relative velocityphys.veloc;arith.difffloat