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Title: RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES

Abstract

Determining the virial factor of the broad-line region gas is crucial for calibrating active galactic nucleus black hole mass estimators, since the measured line-of-sight velocity needs to be converted into the intrinsic virial velocity. The average virial factor has been empirically calibrated based on the M{sub BH}-{sigma}{sub *} relation of quiescent galaxies, but the claimed values differ by a factor of two in recent studies. We investigate the origin of the difference by measuring the M{sub BH}-{sigma}{sub *} relation using an updated galaxy sample from the literature and explore the dependence of the virial factor on various fitting methods. We find that the discrepancy is primarily caused by the sample selection, while the difference stemming from the various regression methods is marginal. However, we generally prefer the FITEXY and Bayesian estimators based on Monte Carlo simulations for the M{sub BH}-{sigma}{sub *} relation. In addition, the choice of independent variable in the regression leads to {approx}0.2 dex variation in the virial factor inferred from the calibration process. Based on the determined virial factor, we present the updated M{sub BH}-{sigma}{sub *} relation of local active galaxies.

Authors:
;  [1]; ;  [2]
  1. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
  2. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
Publication Date:
OSTI Identifier:
22089802
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal, Supplement Series
Additional Journal Information:
Journal Volume: 203; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0067-0049
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; BLACK HOLES; CALIBRATION; COMPUTERIZED SIMULATION; GALAXIES; GALAXY NUCLEI; MASS; MONTE CARLO METHOD; VARIATIONS

Citation Formats

Park, Daeseong, Woo, Jong-Hak, Kelly, Brandon C., and Treu, Tommaso, E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: bckelly@physics.ucsb.edu, E-mail: tt@physics.ucsb.edu. RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES. United States: N. p., 2012. Web. doi:10.1088/0067-0049/203/1/6.
Park, Daeseong, Woo, Jong-Hak, Kelly, Brandon C., & Treu, Tommaso, E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: bckelly@physics.ucsb.edu, E-mail: tt@physics.ucsb.edu. RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES. United States. doi:10.1088/0067-0049/203/1/6.
Park, Daeseong, Woo, Jong-Hak, Kelly, Brandon C., and Treu, Tommaso, E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: bckelly@physics.ucsb.edu, E-mail: tt@physics.ucsb.edu. Thu . "RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES". United States. doi:10.1088/0067-0049/203/1/6.
@article{osti_22089802,
title = {RECALIBRATION OF THE VIRIAL FACTOR AND M{sub BH}-{sigma}{sub *} RELATION FOR LOCAL ACTIVE GALAXIES},
author = {Park, Daeseong and Woo, Jong-Hak and Kelly, Brandon C. and Treu, Tommaso, E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: bckelly@physics.ucsb.edu, E-mail: tt@physics.ucsb.edu},
abstractNote = {Determining the virial factor of the broad-line region gas is crucial for calibrating active galactic nucleus black hole mass estimators, since the measured line-of-sight velocity needs to be converted into the intrinsic virial velocity. The average virial factor has been empirically calibrated based on the M{sub BH}-{sigma}{sub *} relation of quiescent galaxies, but the claimed values differ by a factor of two in recent studies. We investigate the origin of the difference by measuring the M{sub BH}-{sigma}{sub *} relation using an updated galaxy sample from the literature and explore the dependence of the virial factor on various fitting methods. We find that the discrepancy is primarily caused by the sample selection, while the difference stemming from the various regression methods is marginal. However, we generally prefer the FITEXY and Bayesian estimators based on Monte Carlo simulations for the M{sub BH}-{sigma}{sub *} relation. In addition, the choice of independent variable in the regression leads to {approx}0.2 dex variation in the virial factor inferred from the calibration process. Based on the determined virial factor, we present the updated M{sub BH}-{sigma}{sub *} relation of local active galaxies.},
doi = {10.1088/0067-0049/203/1/6},
journal = {Astrophysical Journal, Supplement Series},
issn = {0067-0049},
number = 1,
volume = 203,
place = {United States},
year = {2012},
month = {11}
}