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Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 220-015
The Astrophysical Journal
  • Aaron J. Barth, University of California - Irvine
  • My L. Nguyen, University of California - Irvine
  • Matthew A. Malkan, University of California - Los Angeles
  • Alexei V. Filippenko, University of California - Berkeley
  • Weidong Li, University of California - Berkeley
  • Varoujan Gorjian, Jet Propulsion Laboratory
  • Michael D. Joner, Brigham Young University - Utah
  • Vardha N. Bennert, University of California - Santa Barbara
  • Janos Botyanski, Lawrence Berkeley National Laboratory
  • S. Bradley Cenko, University of California - Berkeley
  • Michael Childress, Lawrence Berkeley National Laboratory
  • Jieun Choi, University of California - Berkeley
  • Julia M. Comerford, University of Texas at Austin
  • Antonino Cucciara, Lawrence Berkeley National Laboratory
  • Robert da Silva, University of California - Santa Cruz
  • Gaspard Duchêne, University of California - Berkeley
  • Michele Fumagalli, University of California - Santa Cruz
  • Mohan Ganeshalingam, University of California - Berkeley
  • Elinor L. Gates, Lick Observatory
  • Brian F. Gerke, Kavli Institute for Particle Astrophysics and Cosmology
  • Christopher V. Griffith, The Pennsylvania State University
  • Chelsea Harris, University of California - Santa Barbara
  • Eric G. Hintz, Brigham Young University - Utah
  • Eric Hsiao, Lawrence Berkeley National Laboratory
  • Michael T. Kandrashoff, University of California - Berkeley
  • William C. Keel, University of Alabama - Tuscaloosa
  • David Kirkman, University of California - San Diego
  • Io K.W. Kleiser, University of California - Berkeley
  • C. David Laney, Brigham Young University - Utah
  • Jeffrey Lee, University of California - San Diego
  • Liliana Lopez, University of California - San Diego
  • Thomas B. Lowe, Lick Observatory
  • J. Ward Moody, Brigham Young University - Utah
  • Alexzandir Morton, University of California - Berkeley
  • A. M. Nierenberg, University of California - Santa Barbara
  • Peter Nugent, University of California - Berkeley
  • Anna Pancoast, University of California - Santa Barbara
  • Jacob Rex, University of California - Berkeley
  • R. Michael Rich, University of California - Los Angeles
  • Jeffrey M. Silverman, University of California - Berkeley
  • Graeme H. Smith, University of California - Santa Cruz
  • Alessandro Sonnenfeld, University of California - Santa Barbara
  • Nao Suzuki, Lawrence Berkeley National Laboratory
  • David Tytler, University of California - San Diego
  • Jonelle L. Walsh, University of California - Irvine
  • Jong-Hak Woo, Seoul National University
  • Yizhe Yang, University of California - Berkeley
  • Carl Zeisse, University of California - San Diego
Publication Date
5-10-2011
Abstract

The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from Hβ reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from 2010 June through December, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of two change in broad Hβ flux. From cross-correlation measurements, we find that the Hβ light curve has a rest-frame lag of 3.86+0.69 –0.90 days with respect to the V-band continuum variations. We also measure reverberation lags for Hα and Hγ and find an upper limit to the Hδ lag. Combining the Hβ lag measurement with a broad Hβ width of σline = 1590 ± 47 km s–1 measured from the rms variability spectrum, we obtain a virial estimate of M BH = 1.00+0.19 –0.24 × 107 M ☉ for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.

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Citation Information
Aaron J. Barth, My L. Nguyen, Matthew A. Malkan, Alexei V. Filippenko, et al.. "Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 220-015" The Astrophysical Journal Vol. 732 Iss. 2 (2011)
Available at: http://works.bepress.com/vbennert/36/