학술논문
REVERBERATION MAPPING OF THE KEPLER FIELD AGN KA1858+4850
Document Type
article
Author
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
Source
The Astrophysical Journal. 795(1)
Subject
Language
Abstract
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 days and τJAVELINdays. The Hβ rms line profile has a width of σline = 770 ± 49 km s-1. Combining these two results and assuming a virial scale factor of f = 5.13, we obtained a virial estimate of for the mass of the central black hole and an Eddington ratio of L/L 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.