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Title: ARE OUTFLOWS BIASING SINGLE-EPOCH C IV BLACK HOLE MASS ESTIMATES?

Abstract

We use a combination of reverberation mapping data and single-epoch (SE) spectra of the C IV emission line in a sample of both low- and high-redshift active galactic nuclei to investigate sources of the discrepancies between C IV- and H{beta}-based SE black hole (BH) mass estimates. We find that for all reverberation mapped sources, there is a component of the line profile that does not reverberate, and the velocity characteristics of this component vary from object to object. The differing strength and properties of this non-variable component are responsible for much of the scatter in C IV-based BH masses compared to H{beta} masses. The C IV mass bias introduced by this non-variable component is correlated with the shape of the C IV line, allowing us to make an empirical correction to the BH mass estimates. Using this correction and accounting for other sources of scatter, such as poor data quality and data inhomogeneity, reduces the scatter between the C IV and H{beta} masses in our sample by a factor of {approx}2, to only {approx}0.2 dex. We discuss the possibility that this non-variable C IV component originates in an orientation-dependent outflow from either the proposed broad-line region disk wind or themore » intermediate-line region, a high-velocity inner extension of the narrow-line region.« less

Authors:
 [1]
  1. Dark Cosmology Centre, Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark)
Publication Date:
OSTI Identifier:
22086458
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCOUNTING; BLACK HOLES; CARBON IONS; CORRECTIONS; EMISSION SPECTRA; GALAXIES; GALAXY NUCLEI; MAPPING; MASS; ORIENTATION; PHOTON EMISSION; QUASARS; RED SHIFT; STELLAR WINDS; VELOCITY

Citation Formats

Denney, K. D., E-mail: kelly@dark-cosmology.dk. ARE OUTFLOWS BIASING SINGLE-EPOCH C IV BLACK HOLE MASS ESTIMATES?. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/1/44.
Denney, K. D., E-mail: kelly@dark-cosmology.dk. ARE OUTFLOWS BIASING SINGLE-EPOCH C IV BLACK HOLE MASS ESTIMATES?. United States. doi:10.1088/0004-637X/759/1/44.
Denney, K. D., E-mail: kelly@dark-cosmology.dk. Thu . "ARE OUTFLOWS BIASING SINGLE-EPOCH C IV BLACK HOLE MASS ESTIMATES?". United States. doi:10.1088/0004-637X/759/1/44.
@article{osti_22086458,
title = {ARE OUTFLOWS BIASING SINGLE-EPOCH C IV BLACK HOLE MASS ESTIMATES?},
author = {Denney, K. D., E-mail: kelly@dark-cosmology.dk},
abstractNote = {We use a combination of reverberation mapping data and single-epoch (SE) spectra of the C IV emission line in a sample of both low- and high-redshift active galactic nuclei to investigate sources of the discrepancies between C IV- and H{beta}-based SE black hole (BH) mass estimates. We find that for all reverberation mapped sources, there is a component of the line profile that does not reverberate, and the velocity characteristics of this component vary from object to object. The differing strength and properties of this non-variable component are responsible for much of the scatter in C IV-based BH masses compared to H{beta} masses. The C IV mass bias introduced by this non-variable component is correlated with the shape of the C IV line, allowing us to make an empirical correction to the BH mass estimates. Using this correction and accounting for other sources of scatter, such as poor data quality and data inhomogeneity, reduces the scatter between the C IV and H{beta} masses in our sample by a factor of {approx}2, to only {approx}0.2 dex. We discuss the possibility that this non-variable C IV component originates in an orientation-dependent outflow from either the proposed broad-line region disk wind or the intermediate-line region, a high-velocity inner extension of the narrow-line region.},
doi = {10.1088/0004-637X/759/1/44},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}