학술논문
Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies
Document Type
article
Author
Fausnaugh, MM; Starkey, DA; Horne, Keith; Kochanek, CS; Peterson, BM; Bentz, MC; Denney, KD; Grier, CJ; Grupe, D; Pogge, RW; De Rosa, G; Adams, SM; Barth, AJ; Beatty, Thomas G; Bhattacharjee, A; Borman, GA; Boroson, TA; Bottorff, MC; Brown, Jacob E; Brown, Jonathan S; Brotherton, MS; Coker, CT; Crawford, SM; Croxall, KV; Eftekharzadeh, Sarah; Eracleous, Michael; Joner, MD; Henderson, CB; Holoien, TW-S; Hutchison, T; Kaspi, Shai; Kim, S; King, Anthea L; Li, Miao; Lochhaas, Cassandra; Ma, Zhiyuan; MacInnis, F; Manne-Nicholas, ER; Mason, M; Montuori, Carmen; Mosquera, Ana; Mudd, Dale; Musso, R; Nazarov, SV; Nguyen, ML; Okhmat, DN; Onken, Christopher A; Ou-Yang, B; Pancoast, A; Pei, L; Penny, Matthew T; Poleski, Radosław; Rafter, Stephen; Romero-Colmenero, E; Runnoe, Jessie; Sand, David J; Schimoia, Jaderson S; Sergeev, SG; Shappee, BJ; Simonian, Gregory V; Somers, Garrett; Spencer, M; Stevens, Daniel J; Tayar, Jamie; Treu, T; Valenti, Stefano; Van Saders, J; Villanueva, S; Villforth, C; Weiss, Yaniv; Winkler, H; Zhu, W
Source
The Astrophysical Journal. 854(2)
Subject
Language
Abstract
We present optical continuum lags for two Seyfert 1 galaxies, MCG+08-11-011 and NGC 2617, using monitoring data from a reverberation mapping campaign carried out in 2014. Our light curves span the ugriz filters over four months, with median cadences of 1.0 and 0.6 days for MCG+08-11-011 and NGC 2617, respectively, combined with roughly daily X-ray and near-UV data from Swift for NGC 2617. We find lags consistent with geometrically thin accretion-disk models that predict a lag-wavelength relation of τ ∝ λ 4/3. However, the observed lags are larger than predictions based on standard thin-disk theory by factors of 3.3 for MCG+08-11-011 and 2.3 for NGC 2617. These differences can be explained if the mass accretion rates are larger than inferred from the optical luminosity by a factor of 4.3 in MCG+08-11-011 and a factor of 1.3 in NGC 2617, although uncertainty in the SMBH masses determines the significance of this result. While the X-ray variability in NGC 2617 precedes the UV/optical variability, the long (2.6 day) lag is problematic for coronal reprocessing models.