J/ApJ/882/4 SDSS-RM project: Hα, Hβ & MgII lines (Wang+, 2019)
The Sloan Digital Sky Survey Reverberation Mapping project: low-ionization
broad-line widths and implications for virial black hole mass estimation.
Wang S., Shen Y., Jiang L., Horne K., Brandt W.N., Grier C.J., Ho L.C.,
Homayouni Y., Li J.I.-H., Schneider D.P., Trump J.R.
<Astrophys. J., 882, 4 (2019)>
=2019ApJ...882....4W 2019ApJ...882....4W
ADC_Keywords: QSOs; Line Profiles; Velocity dispersion; Redshifts;
Spectra, optical; Surveys
Keywords: black hole physics; galaxies: active; line: profiles;
quasars: general; surveys
Abstract:
The width of the broad emission lines in quasars is commonly
characterized by either the FWHM or the square root of the second
moment of the line profile (σline) and used as an indicator of
the virial velocity of the broad-line region (BLR) in the estimation
of black hole (BH) mass. We measure FWHM and σline for Hα,
Hβ, and MgII broad lines in both the mean and rms spectra of a
large sample of quasars from the Sloan Digital Sky Survey
Reverberation Mapping project. We introduce a new quantitative recipe
to measure σline that is reproducible, is less susceptible to
noise and blending in the wings, and scales with the intrinsic width
of the line. We compare the four definitions of line width (FWHM and
σline in mean and rms spectra, respectively) for each of the
three broad lines and among different lines. There are strong
correlations among different width definitions for each line,
providing justification for using the line width measured in
single-epoch spectroscopy as a virial velocity indicator. There are
also strong correlations among different lines, suggesting that
alternative lines to Hβ can be used to estimate virial BH masses.
We further investigate the correlations between virial BH masses using
different line width definitions and the stellar velocity dispersion
of the host galaxies and the dependence of line shape (characterized
by the ratio FWHM/σline) on physical properties of the quasar.
Our results provide further evidence that FWHM is more sensitive to
the orientation of a flattened BLR geometry than σline, but the
overall comparison between the virial BH mass and host stellar
velocity dispersion does not provide conclusive evidence that one
particular width definition is significantly better than the others.
Description:
SDSS-RM is a dedicated reverberation mapping (RM) project that uses
the SDSS BOSS spectrograph on the 2.5m SDSS telescope to monitor
849 broad-line quasars in a single 7°2 field over a broad
redshift and luminosity range. A detailed description of the sample
characterization is presented in Shen+ (2019ApJS..241...34S 2019ApJS..241...34S). From the
commencement of this program as part of SDSS-III, SDSS-RM obtained
32 spectroscopic epochs in 2014 at an average cadence of ∼4 days and
will continue through 2020 with 6-12 spectroscopic epochs per
observing season.
The spectroscopic data used in this work are the 32 epochs taken
during 2014. Both the individual epoch spectra and the co-added
spectra during this period are used in our analysis. The wavelength
coverage of BOSS spectrographs is ∼3650-10400Å, with a spectral
resolution of R∼2000.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 462 849 Line width measurements
datafile3.fits 2880 98 Original FITS file of Table 3
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
VII/286 : SDSS quasar catalog, fourteenth data release (Paris+, 2018)
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/753/125 : NIR spectroscopy follow-up of 60 SDSS-DR7 QSOs (Shen+, 2012)
J/ApJ/805/96 : SDSS-RM project: velocity dispersions of QSOs (Shen+, 2015)
J/ApJS/217/26 : Lick AGN monitoring 2011: light curves (Barth+, 2015)
J/MNRAS/454/3864 : Orientation & QSO black hole masses (Brotherton+ 2015)
J/ApJS/216/4 : SDSS-RM project: technical overview (Shen+, 2015)
J/ApJ/805/96 : SDSS-RM project: velocity dispersions of QSOs (Shen+, 2015)
J/ApJ/818/30 : Lag measurements for 15 z<0.8 QSOs from SDSS-RM (Shen+, 2016)
J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)
J/ApJ/851/21 : SDSS RM project first year of observations (Grier+, 2017)
J/ApJS/235/11 : Absorption features in SDSS. I. MgII doublets (Chen+, 2018)
J/ApJS/250/10 : SDSS-RM AGNs CFHT & Bok photometry over 4yrs (Kinemuchi+, 2020)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- RMID [0/848]? SDSS-RM identification number
5- 22 A18 --- SDSS SDSS name (HHMMSS.ss+DDMMSS.s; J2000)
(SDSS_name)
24- 34 F11.7 deg RAdeg [211.2/216.2] Right ascension (J2000) (RA)
36- 45 F10.7 deg DEdeg [51.6/54.6] Declination (J2000) (DEC)
47- 55 F9.7 --- z [0.11/4.4] Redshift (Redshift)
57- 67 F11.6 km/s sigma [43/380]?=0 Stellar velocity dispersion
(SIGMA_HOST1)
69- 79 F11.6 km/s e_sigma [1.8/74.3]?=0 Sigma uncertainty
(SIGMA_HOST2)
81- 91 F11.6 km/s FWHMHa [1035/8700]?=0 Hα FWHM in mean
spectra (HALPHAFWHMmean1)
93- 103 F11.6 km/s e_FWHMHa [32/1341]?=0 FWHMHa uncertainty
(HALPHAFWHMmean2)
105- 115 F11.6 km/s sigHa [503/3459]?=0 Hα σline in
mean spectra (HALPHASIGMAmean1)
117- 127 F11.6 km/s e_sigHa [11/563]?=0 SigHa uncertainty
(HALPHASIGMAmean2)
129- 139 F11.6 km/s FWHMHar [1035/9399]?=0 Hα FWHM in rms spectra
(HALPHAFWHMrms1)
141- 151 F11.6 km/s e_FWHMHar [28/1922]?=0 FWHMHar uncertainty
(HALPHAFWHMrms2)
153- 163 F11.6 km/s sigHar [474/3942]?=0 Hα σline in rms
spectra (HALPHASIGMArms1)
165- 175 F11.6 km/s e_sigHar [1/308]?=0 SigHar uncertainty
(HALPHASIGMArms2)
177- 188 F12.6 km/s FWHMHb [34/11804]?=0 Hβ FWHM in mean spectra
(HBETAFWHMmean1)
190- 201 F12.6 km/s e_FWHMHb [29/2620]?=0 FWHMHb uncertainty
(HBETAFWHMmean2)
203- 213 F11.6 km/s sigHb [666/4385]?=0 Hβ σline in mean
spectra (HBETASIGMAmean1)
215- 225 F11.6 km/s e_sigHb [9/925]?=0 SigHb uncertainty
(HBETASIGMAmean2)
227- 238 F12.6 km/s FWHMHbr [622/10607]?=0 Hβ FWHM in rms spectra
(HBETAFWHMrms1)
240- 251 F12.6 km/s e_FWHMHbr [16/2623]?=0 FWHMHbr uncertainty
(HBETAFWHMrms2)
253- 263 F11.6 km/s sigHbr [427.3/5091]?=0 Hβ σline in
rms spectra (HBETASIGMArms1)
265- 275 F11.6 km/s e_sigHbr [0.09/210]?=0 SigHbr uncertainty
(HBETASIGMArms2)
277- 288 F12.6 km/s FWHMMgII [482/45728]?=0 MgII FWHM in mean spectra
(MGIIFWHMmean1)
290- 301 F12.6 km/s e_FWHMMgII [21/21482]?=0 FWHMMgII uncertainty
(MGIIFWHMmean2)
303- 314 F12.6 km/s sigMgII [721/42134]?=0 MgII σline in mean
spectra (MGIISIGMAmean1)
316- 327 F12.6 km/s e_sigMgII [6/2399]?=0 SigMgII uncertainty
(MGIISIGMAmean2)
329- 340 F12.6 km/s FWHMMgIIr [68/10732]?=0 MgII FWHM in rms spectra
(MGIIFWHMrms1)
342- 353 F12.6 km/s e_FWHMMgIIr [10/2883]?=0 FWHMMgIIr uncertainty
(MGIIFWHMrms2)
355- 365 F11.6 km/s sigMgIIr [714.2/6488]?=0 MgII σline in rms
spectra (MGIISIGMArms1)
367- 377 F11.6 km/s e_sigMgIIr [0.006/1300]?=0 SigMgIIr uncertainty
(MGIISIGMArms2)
379- 387 F9.6 --- FeII [-0/4.85] Optical FeII strength
(relative to broad Hβ) (R_FE)
389- 397 F9.6 --- Chi2cHa [0/32.1] Reduced χ2 of the continuum
fit around Hα (REDCHI2_CONTINUUMFIT1)
399- 407 F9.6 --- Chi2cHb [0/35.2] Reduced χ2 of the continuum
fit around Hβ (REDCHI2_CONTINUUMFIT2)
409- 417 F9.6 --- Chi2cMgII [0/77.9] Reduced χ2 of the continuum
fit around MgII (REDCHI2_CONTINUUMFIT3)
419- 428 F10.6 --- Chi2Ha [0/539.2] Reduced χ2 of line fit of
Hα (REDCHI2_LINEFIT1)
430- 439 F10.6 --- Chi2Hb [0/56.7] Reduced χ2 of line fit of
Hβ (REDCHI2_LINEFIT2)
441- 450 F10.6 --- Chi2MgII [0/44.9] Reduced χ2 of line fit of
MgII (REDCHI2_LINEFIT3)
452 I1 --- mHa [0/1] Is in the Hα good mean
subsample (1=yes) (FLAGGOODMEAN_HALPHA)
454 I1 --- rHa [0/1] Is in the Hα good rms subsample
(1=yes) (FLAGGOODRMS_HALPHA)
456 I1 --- mHb [0/1] Is in the Hβ good mean subsample
(1=yes) (FLAGGOODMEAN_HBETA)
458 I1 --- rHb [0/1] Is in the Hβ good rms subsample
(1=yes) (FLAGGOODRMS_HBETA)
460 I1 --- mMgII [0/1] Is in the MgII good mean subsample
(1=yes) (FLAGGOODMEAN_MGII)
462 I1 --- rMgII [0/1] Is in the MgII good rms subsample
(1=yes) (FLAGGOODRMS_MGII)
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Jan-2021