J/MNRAS/469/3163 Properties of BAL quasars (McGraw+, 2017)
Broad absorption line disappearance and emergence using multiple-epoch
spectroscopy from the Sloan Digital Sky Survey.
McGraw S.M., Brandt W.N., Grier C.J., Filiz Ak N., Hall P.B.,
Schneider D.P., Anderson S.F., Green P.J., Hutchinson T.A., Macleod C.L.,
Vivek M.
<Mon. Not. R. Astron. Soc., 469, 3163-3184 (2017)>
=2017MNRAS.469.3163M 2017MNRAS.469.3163M (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Active gal. nuclei ; Radial velocities ; Equivalent widths
Keywords: galaxies: active - quasars: absorption lines - quasars: general
Abstract:
We investigate broad absorption line (BAL) disappearance and emergence
using a 470 BAL-quasar sample over ≤0.10-5.25 rest-frame years with
at least three spectroscopic epochs for each quasar from the Sloan
Digital Sky Survey. We identify 14 disappearing BALs over ≤1.73-4.62
rest-frame years and 18 emerging BALs over ≤1.46-3.66 rest-frame
years associated with the CIVλλ1548,1550 and/or
SiIVλλ1393,1402 doublets, and report on their
variability behaviour. BAL quasars in our data set exhibit
disappearing/emerging C IV BALs at a rate of 2.3+0.9-0.7 and
3.0+1.0-0.8 per cent, respectively, and the frequency for BAL to
non-BAL quasar transitions is 1.7+0.8-0.6 per cent. We detect four
re-emerging BALs over ≤3.88 rest-frame years on average and three
re-disappearing BALs over ≤4.15 rest-frame years on average, the
first reported cases of these types. We infer BAL lifetimes along the
line of sight to be nominally ≤100-1000yr using disappearing CIV
BALs in our sample. Interpretations of (re-)emerging and
(re-)disappearing BALs reveal evidence that collectively supports both
transverse-motion and ionization-change scenarios to explain BAL
variations. We constrain a nominal CIV/SiIV BAL-outflow location of
≤100pc from the central source and a radial size of ≥1x10-7pc
(0.02au) using the ionization-change scenario, and constrain a nominal
outflow location of ≤0.5pc and a transverse size of ∼0.01pc using the
transverse-motion scenario. Our findings are consistent with previous
work, and provide evidence in support of BALs tracing compact flow
geometries with small filling factors.
Description:
We have conducted a quantitative, systematic investigation of CIV and
SiIV BAL disappearance and emergence using a sample of 470 BAL
quasars over ≤0.10-5.25yr in the rest frame with at least three
spectroscopic epochs for each quasar from the SDSS, BOSS and TDSS
surveys.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 2228 BAL measurements and associated observations
of 470 QSOs
table2.dat 82 34 Properties of BAL quasars with pristine
disappearing and emerging BALs
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See also:
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name BAL quasar name (JHHMMSS.ss+DDMMSS.s)
23- 37 A15 --- PMF Plate-MJD-Fiber number for the associated
SDSS spectrum
41- 46 I6 km/s Vmin Minimum BAL velocity (1)
50- 55 I6 km/s Vmax Maximum BAL velocity (1)
59- 63 I5 km/s BI Balnicity index
67- 70 F4.1 0.1nm EW Rest-frame equivalent width
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Note (1): BAL velocities are calculated with respect to the average wavelength
of the CIV doublet (i.e., 1549.062Å).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- Flag [DE] Disappearing (D) or Emerging (E) BALs
3- 21 A19 --- Name BAL-quasar name (JHHMMSS.ss+DDMMSS.s)
23- 24 A2 --- n_Name [BW ] Note on Name (1)
26- 29 F4.2 --- z Emission-line redshift (Hewett & Wild,
2010, Cat. J/MNRAS/405/2302)
31- 35 F5.1 mag iMAG Absolute i-band magnitude corrected to z=2
(Shen et al. 2011)
37- 40 F4.1 [10-7W] logLbol Bolometric luminosity (Shen et al., 2011,
Cat. J/ApJS/194/45)
42- 45 F4.1 [Msun] logMass ? SMBH mass (Shen et al., 2011,
Cat. J/ApJS/194/45)
47- 50 F4.1 [-] logLbol/LEdd ? Eddington ratio (Shen et al., 2011,
Cat. J/ApJS/194/45)
52- 54 I3 --- R Radio-loudness parameter
(R=f6cm/f2500A; Shen et al., 2011,
Cat. J/ApJS/194/45) (2)
56- 61 I6 km/s vBAL Disappearing/emerging BAL velocity
(see Section 3.2) (3)
63- 66 I4 km/s BI Disappearing/emerging balnicity index
(see Section 3.2) (3)
68- 72 F5.1 0.1nm DEW Disappearing/emerging change in EW
(see Section 4.1)
74- 77 F4.1 --- DEW/EW Disappearing/emerging change in
fractional EW (see Section 4.1)
79- 82 A4 --- Ion Associated ion(s) of the
disappearing/emerging BAL(s)
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Note (1): Note as follows:
B = quasars with a re-emerging or re-disappearing BAL (see Sect. 4.2 and 4.3)
W = sources that undergo a BAL to non-BAL quasar transition (see Section 4.1)
Note (2): BAL quasars with R=0 were not detected by the FIRST survey.
Note (3): Values for vBAL and BI for disappearing BALs were measured using the
SDSS epoch for each source, while the BOSS epoch was used to measure these
quantities for emerging BALs.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Apr-2020