Reverberation mapping of the Kepler field AGN KA1858+4850
- Department of Physics and Astronomy, University of California, Irvine, CA, 92697 (United States)
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
- Department of Physics and Astronomy, Appalachian State University, Boone, NC 28608 (United States)
- Department of Physics and Astronomy, N283 ESC, Brigham Young University, Provo, UT 84602 (United States)
- Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
- Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
- Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
- Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States)
- Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305 (United States)
- Lick Observatory, P.O. Box 85, Mt. Hamilton, CA 95140 (United States)
- Department of Physics, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States)
- Department of Physics, University of California, San Diego, La Jolla, CA 92093 (United States)
KA1858+4850 is a narrow-line Seyfert 1 galaxy at redshift 0.078 and is among the brightest active galaxies monitored by the Kepler mission. We have carried out a reverberation mapping campaign designed to measure the broad-line region size and estimate the mass of the black hole in this galaxy. We obtained 74 epochs of spectroscopic data using the Kast Spectrograph at the Lick 3 m telescope from 2012 February to November, and obtained complementary V-band images from five other ground-based telescopes. We measured the Hβ light curve lag with respect to the V-band continuum light curve using both cross-correlation techniques (CCF) and continuum light curve variability modeling with the JAVELIN method and found rest-frame lags of τ{sub CCF}=13.53{sub −2.32}{sup +2.03} days and τ {sub JAVELIN} =13.15{sub −1.00}{sup +1.08} days. The Hβ rms line profile has a width of σ{sub line} = 770 ± 49 km s{sup –1}. Combining these two results and assuming a virial scale factor of f = 5.13, we obtained a virial estimate of M{sub BH}=8.06{sub −1.72}{sup +1.59}×10{sup 6}M{sub ⊙} for the mass of the central black hole and an Eddington ratio of L/L {sub Edd} ≈ 0.2. We also obtained consistent but slightly shorter emission-line lags with respect to the Kepler light curve. Thanks to the Kepler mission, the light curve of KA1858+4850 has among the highest cadences and signal-to-noise ratios ever measured for an active galactic nucleus; thus, our black hole mass measurement will serve as a reference point for relations between black hole mass and continuum variability characteristics in active galactic nuclei.
- OSTI ID:
- 22370320
- Journal Information:
- Astrophysical Journal, Vol. 795, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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