J/ApJ/753/L2 Reverberation mapping of AGNs (Assef+, 2012)
The importance of broad emission line widths in single-epoch black hole mass
estimates.
Assef R.J., Frank S., Grier C.J., Kochanek C.S., Denney K.D., Peterson B.M.
<Astrophys. J., 753, L2 (2012)>
=2012ApJ...753L...2A 2012ApJ...753L...2A
ADC_Keywords: Active gal. nuclei ; Spectroscopy
Keywords: galaxies: active; quasars: emission lines
Abstract:
Estimates of the mass of super-massive black holes (BHs) in distant
active galactic nuclei (AGNs) can be obtained efficiently only through
single-epoch (SE) spectra, using a combination of their broad emission
line widths and continuum luminosities. Yet the reliability and
accuracy of the method and the resulting mass estimates, MBH, remain
uncertain. A recent study by Croom using a sample of Sloan Digital Sky
Survey, 2dF QSO Redshift Survey, and 2dF-SDSS LRG and QSO Survey
quasars suggests that line widths contribute little information about
the BH mass in these SE estimates and can be replaced by a constant
value without significant loss of accuracy. In this Letter, we use a
sample of nearby reverberation-mapped AGNs to show that this
conclusion is not universally applicable. We use the bulge luminosity
(LBulge) of these local objects to test how well the known
MBH-LBulgecorrelation is recovered when using randomly assigned
line widths instead of the measured ones to estimate MBH. We find
that line widths provide significant information about MBH, and that
for this sample, the line width information is just as significant as
that provided by the continuum luminosities. We discuss the effects of
observational biases upon the analysis of Croom and suggest that the
results can probably be explained as a bias of flux-limited, shallow
quasar samples.
Description:
In order to understand the importance of line widths in single-epoch
MBH estimates, we use a sample of 34 nearby AGNs observed in
reverberation mapping (RM; Blandford & McKee, 1982ApJ...255..419B 1982ApJ...255..419B;
Peterson B.M., 1993PASP..105..247P 1993PASP..105..247P) campaigns with bulge luminosity
measurements at 5100Å, LBulge, by Bentz et al.
(2009ApJ...697..160B 2009ApJ...697..160B) using the Hubble Space Telescope.
Every object in our sample has been the subject of at least one RM
observational campaign, and many for two or more. For each object we
use the mean optical spectrum of each RM campaign, and we treat each
of the 62 mean spectra as independent objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 53 62 Reverberation mapping properties for 34 AGNs
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See also:
J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012)
J/ApJS/201/29 : Velocity dispersions in active galaxies (Harris+, 2012)
J/ApJ/742/68 : HST observations of low-mass BH host galaxies (Jiang+, 2011)
J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010)
J/ApJ/702/1353 : Hβ and V-band light curves of NGC 4051 (Denney+, 2009)
J/ApJ/699/800 : Mass functions of active black holes (Vestergaard+, 2009)
J/ApJ/670/92 : New sample of low-mass black holes in AGN (Greene+, 2007)
J/ApJ/667/131 : Mass function of active black holes (Greene+, 2007)
J/ApJS/168/1 : Black hole mass estimates (Kelly+, 2007)
J/ApJ/641/L21 : Black hole mass & velocity dispersion relation (Greene+, 2006)
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/ApJ/614/91 : Black hole mass and accretion rate of AGNs (Wu+, 2004)
J/ApJ/596/437 : Stellar-mass black holes in the SDSS (Chisholm+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
12- 16 F5.2 [10-7W] L5100 [41.8/46] Log of 510nm luminosity (erg/s)
18- 21 F4.2 [10-7W] e_L5100 [0.03/0.2] Uncertainty in L5100
23- 27 F5.2 [10-7W] LB [42.6/45.1] Log of Bulge luminosity
29- 33 I5 km/s FWHM [799/12694] Full-Width at Half-Maximum of
the line
35- 37 I3 km/s e_FWHM [2/426] Uncertainty in FWHM
39- 42 I4 km/s sigma [953/3744] Line dispersion
44- 46 I3 km/s e_sigma [1/642] Uncertainty in sigma
48 A1 --- l_Nsp Limit flag on Nsp
49- 51 I3 --- Nsp [14/194] Number of spectra used
53 I1 --- Ref Reference (1)
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Note (1): Reference as follows:
1 = Peterson et al. (2004, Cat. J/ApJ/613/682) and references therein;
2 = Denney et al. (2010ApJ...721..715D 2010ApJ...721..715D);
3 = Onken & Peterson (2002ApJ...572..746O 2002ApJ...572..746O);
4 = Denney et al. (2009, Cat. J/ApJ/702/1353);
5 = Denney et al. (2006ApJ...653..152D 2006ApJ...653..152D);
6 = Bentz et al. (2007ApJ...662..205B 2007ApJ...662..205B);
7 = Grier et al. (2008ApJ...688..837G 2008ApJ...688..837G).
Mean line-widths for the spectra of Peterson et al. (2004,
Cat. J/ApJ/613/682) and Onken & Peterson (2002ApJ...572..746O 2002ApJ...572..746O) are
presented by Collin et al. (2006A&A...456...75C 2006A&A...456...75C).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 25-Feb-2014