Broad-Line Reverberation In The Kepler-Field Seyfert Galaxy Zw 229-015

Access full-text files




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

Journal Title

Journal ISSN

Volume Title



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 H beta 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 H beta flux. From cross-correlation measurements, we find that the H beta light curve has a rest-frame lag of 3.86(-0.90)(+0.69) days with respect to the V-band continuum variations. We also measure reverberation lags for H alpha and H gamma and find an upper limit to the H delta lag. Combining the H beta lag measurement with a broad H beta width of sigma(line) = 1590 +/- 47 km s(-1) measured from the rms variability spectrum, we obtain a virial estimate of M-BH = 1.00(-0.24)(+0.19) x 10(7) M-circle dot 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.



LCSH Subject Headings


Barth, Aaron J., My L. Nguyen, Matthew A. Malkan, Alexei V. Filippenko, Weidong Li, Varoujan Gorjian, Michael D. Joner et al. "Broad-line Reverberation in the Kepler-field Seyfert Galaxy Zw 229-015." The Astrophysical Journal, Vol. 732, No. 2 (May., 2011): 121.