학술논문
BROAD-LINE REVERBERATION IN THE KEPLER-FIELD SEYFERT GALAXY Zw 229-015
Document Type
article
Author
Barth, Aaron J; Nguyen, My L; Malkan, Matthew A; Filippenko, Alexei V; Li, Weidong; Gorjian, Varoujan; Joner, Michael D; Bennert, Vardha Nicola; Botyanszki, Janos; Cenko, S Bradley; Childress, Michael; Choi, Jieun; Comerford, Julia M; Cucciara, Antonino; da Silva, Robert; Duchêne, Gaspard; Fumagalli, Michele; Ganeshalingam, Mohan; Gates, Elinor L; Gerke, Brian F; Griffith, Christopher V; Harris, Chelsea; Hintz, Eric G; Hsiao, Eric; Kandrashoff, Michael T; Keel, William C; Kirkman, David; Kleiser, Io KW; Laney, C David; Lee, Jeffrey; Lopez, Liliana; Lowe, Thomas B; Moody, J Ward; Morton, Alekzandir; Nierenberg, AM; Nugent, Peter; Pancoast, Anna; Rex, Jacob; Rich, R Michael; Silverman, Jeffrey M; Smith, Graeme H; Sonnenfeld, Alessandro; Suzuki, Nao; Tytler, David; Walsh, Jonelle L; Woo, Jong-Hak; Yang, Yizhe; Zeisse, Carl
Source
The Astrophysical Journal. 732(2)
Subject
Language
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. © 2011. The American Astronomical Society. All rights reserved.