First results from the lick AGN monitoring project: the mass of the black hole in ARP 151

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
Nicola 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, Princeton University
Marton G. Hidas, University of California - Irvine
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
Frank J.D. Serduke, University of California - Berkeley
Joshua H. Shiode, 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 - Santa Barbara
Yuzuru Yoshii, University of Tokyo

Recommended Citation

Published in The Astrophysical Journal Letters, Volume 689, Issue 1, December 10, 2008, pages L21-L24.

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

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 13 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~10⁶-10⁷ M_☉. We present here the first results from this project—the mass of the central black hole in Arp 151. Strong variability throughout the campaign led to an exceptionally clean Hβ lag measurement in this object of 4.25_−0.66^+0.68 days in the observed frame. Coupled with the width of the Hβ emission line in the variable spectrum, we determine a black hole mass of (7.1 ± 1.2) × 10⁶ M_☉, assuming the Onken et al. normalization for reverberation-based virial masses. We also find velocity-resolved lag information within the Hβ emission line which clearly shows infalling gas in the Hβ-emitting region. Further detailed analysis may lead to a full model of the geometry and kinematics of broad line region gas around the central black hole in Arp 151.

Disciplines

Physics

Copyright

2008 IOP Publishing.