학술논문
Reverberation mapping of the kepler field agn KA1858+4850
Document Type
article
Author
Pei, L; Barth, AJ; Aldering, GS; Briley, MM; Carroll, CJ; Carson, DJ; Cenko, SB; Clubb, KI; Cohen, DP; Cucchiara, A; Desjardins, TD; Edelson, R; Fang, JJ; Fedrow, JM; Filippenko, AV; Fox, OD; Furniss, A; Gates, EL; Gregg, M; Gustafson, S; Horst, JC; Joner, MD; Kelly, PL; Lacy, M; Laney, CD; Leonard, DC; Li, W; Malkan, MA; Margon, B; Neeleman, M; Nguyen, ML; Prochaska, JX; Ross, NR; Sand, DJ; Searcy, KJ; Shivvers, IS; Silverman, JM; Smith, GH; Suzuki, N; Smith, KL; Tytler, D; Werk, JK; Worseck, G
Source
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.