The lick AGN monitoring project: broad-line region radii and black hole masses from reverberation mapping of Hß

Author Info

Misty C. Bentz, University of California - Irvine
Jonelle L. Walsh, University of California - Irvine
Aaron J. Barth, University of California - Irvine
Nairn Baliber, University of California - Santa Barbara
Vardha N. Bennert, University of California - Santa BarbaraFollow
Gabriela Canalizo, University of California - Riverside
Alexei V. Filippenko, University of California - Berkeley
Mohan Ganeshalingam, University of California - Berkeley
Elinor L. Gates, Lick Observatory
Jenny E. Greene, University of California - Santa Barbara
Marton G. Hidas, University of California - Santa Barbara
Kyle D. Hiner, University of California - Riverside
Nicholas Lee, University of California - Berkeley
Weidong Li, University of California - Berkeley
Matthew A. Malkan, University of California - Los Angeles
Takeo Minezaki, University of Tokyo
Yu Sakata, University of Tokyo
Frank J.D. Serduke, University of California - Berkeley
Jeffrey M. Silverman, University of California - Berkeley
Thea N. Steele, University of California - Berkeley
Daniel Stern, California Institute of Technology
Rachel A. Street, University of California - Santa Barbara
Carol E. Thornton, University of California - Irvine
Tommaso Treu, University of California - Santa Barbara
Xiaofeng Wang, University of California - Berkeley
Jong-Hak Woo, University of California - Los Angeles
Yuzuru Yoshii, University of Tokyo

Recommended Citation

Published in The Astrophysical Journal, Volume 705, Issue 1, November 1, 2009, pages 199-217.

NOTE: At the time of publication, the author Vardha Nicola Bennert was not yet affiliated with Cal Poly.

The definitive version is available at https://doi.org/10.1088/0004-637X/705/1/199.

Abstract

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~10⁶-10⁷ M _☉ and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hβ emission. We present here the light curves for all the objects in this sample and the subsequent Hβ time lags for the nine objects where these measurements were possible. The Hβ lag time is directly related to the size of the broad-line region (BLR) in AGNs, and by combining the Hβ lag time with the measured width of the Hβ emission line in the variable part of the spectrum, we determine the virial mass of the central supermassive black hole in these nine AGNs. The absolute calibration of the black hole masses is based on the normalization derived by Onken et al., which brings the masses determined by reverberation mapping into agreement with the local M _BH-σrelationship for quiescent galaxies. We also examine the time lag response as a function of velocity across the Hβ line profile for six of the AGNs. The analysis of four leads to rather ambiguous results with relatively flat time lags as a function of velocity. However, SBS 1116+583A exhibits a symmetric time lag response around the line center reminiscent of simple models for circularly orbiting BLR clouds, and Arp 151 shows an asymmetric profile that is most easily explained by a simple gravitational infall model. Further investigation will be necessary to fully understand the constraints placed on the physical models of the BLR by the velocity-resolved response in these objects.

Disciplines

Physics

Copyright

2009 IOP Publishing.