REVERBERATION MAPPING OF THE KEPLER FIELD AGN KA1858+4850

• Published in: The Astrophysical journal 2014-11, Vol.795 (1), p.38
• Main Authors: Pei, Liuyi, Barth, Aaron J., Aldering, Greg S., Briley, Michael M., Carroll, Carla J., Carson, Daniel J., Cenko, S. Bradley, Clubb, Kelsey I., Cohen, Daniel P., Cucchiara, Antonino, Desjardins, Tyler D., Edelson, Rick, Fang, Jerome J., Fedrow, Joseph M., Filippenko, Alexei V., Fox, Ori D., Furniss, Amy, Gates, Elinor L., Gregg, Michael, Gustafson, Scott, Horst, J. Chuck, Joner, Michael D., Kelly, Patrick L., Lacy, Mark, Laney, C. David, Leonard, Douglas C., Li, Weidong, Malkan, Matthew A., Margon, Bruce, Neeleman, Marcel, Nguyen, My L., Prochaska, J. Xavier, Ross, Nathaniel R., Sand, David J., Searcy, Kinchen J., Shivvers, Isaac S., Silverman, Jeffrey M., Smith, Graeme H., Suzuki, Nao, Smith, Krista Lynne, Tytler, David, Werk, Jessica K., Worseck, Gábor
• Format: Article
• Language: English
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; CORRELATIONS; DESIGN; EMISSION; GALAXIES; GALAXY NUCLEI; MASS; RED SHIFT; SEYFERT GALAXIES; SIGNAL-TO-NOISE RATIO; SIMULATION; TELESCOPES; VISIBLE RADIATION
• ISSN: 1538-4357; 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/795/1/38

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.