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Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies

Fausnaugh, M. M. and Adams, S. M. (2018) Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies. Astrophysical Journal, 854 (2). Art. No. 107. ISSN 1538-4357.

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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.

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Adams, S. M.0000-0001-5855-5939
Additional Information:© 2018 The American Astronomical Society. Received 2017 March 24; revised 2017 December 15; accepted 2017 December 24; published 2018 February 16. M.M.F. acknowledges financial support from a Presidential Fellowship awarded by The Ohio State University Graduate School. NSF grant AST-1008882 supported M.M.F., G.D.R., B.M.P., and R.W.P. M.C.B. gratefully acknowledges support through NSF CAREER grant AST-1253702 to Georgia State University. K.D.D. is supported by an NSF AAPF fellowship awarded under NSF grant AST-1302093. C.S.K. is supported by NSF grant AST-1515876. K.H. acknowledges support from STFC grant ST/M001296/1. This material is based in part upon work supported by the National Science Foundation (NSF) Graduate Research Fellowship Program under Grant No. DGE-0822215, awarded to C.B.H., and A.M.M. acknowledges the support of NSF grant AST-1211146. M.E. thanks the members of the Center for Relativistic Astrophysics at Georgia Tech, where he was based during the observing campaign, for their warm hospitality. J.S.S. acknowledges CNPq, National Council for Scientific and Technological Development, Brazil. J.T. acknowledges support from NSF grant AST-1411685. Work by S.V. Jr. is supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1343012. Work by W.Z. was supported by NSF grant AST-1516842. T.W.-S.H. is supported by the DOE Computational Science Graduate Fellowship, grant number DE-FG02-97ER25308. E.R.C. and S.M.C. gratefully acknowledge the receipt of research grants from the National Research Foundation (NRF) of South Africa. T.T. acknowledges support by the National Science Foundation through grant AST-1412315 "Collaborative Research: New Frontiers in Reverberation Mapping," and by the Packard Foundation through a Packard Research Fellowship. D.J.S. acknowledges support from NSF grants AST-1412504 and AST-1517649. A.J.B. and L.P. have been supported by NSF grant AST-1412693. B.J.S. is supported by NASA through Hubble Fellowship grant HF-51348.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. M.C.B. acknowledges support through grant HST GO-13816 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This research has made use of the XRT Data Analysis Software (XRTDAS), developed under the responsibility of the ASI Science Data Center (ASDC), Italy. This work is based on observations obtained at the MDM Observatory, operated by Dartmouth College, Columbia University, Ohio State University, Ohio University, and the University of Michigan. This paper is partly based on observations collected at the Wise Observatory with the C18 telescope. The C18 telescope and most of its equipment were acquired with a grant from the Israel Space Agency (ISA) to operate a Near-Earth Asteroid Knowledge Center at Tel Aviv University. The Fountainwood Observatory would like to thank the HHMI for its support of science research for undergraduate students at Southwestern University. This research has made use of NASA's Astrophysics Data System, as well as the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Facilities: McGraw-Hill - MDM Observatory's 1m McGraw-Hill Telescope, HST - , Wise Observatory - , Fountainwood Observatory BYU:0.9m - , CrAO:0.7 m - , WIRO - , LCO - , LCOGT - , SSO:1m - , Swift. - Software: Astropy (Astropy Collaboration et al. 2013), IRAF (Tody 1986), Matplotlib (Hunter 2007), Numpy (van der Walt et al. 2011), Scipy (Oliphant 2007).
Funding AgencyGrant Number
Ohio State UniversityUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/M001296/1
NSF Graduate Research FellowshipDGE-0822215
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNSPECIFIED
NSF Graduate Research FellowshipDGE-1343012
Department of Energy (DOE)DE-FG02-97ER25308
National Research Foundation (NRF) South AfricaUNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
NASANAS 5-26555
NASA Hubble FellowshipGO-13816
Subject Keywords:accretion, accretion disks – galaxies: individual (MCG+08-11-011, NGC 2617) – galaxies: Seyfert
Record Number:CaltechAUTHORS:20180221-112144152
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Official Citation:M. M. Fausnaugh et al 2018 ApJ 854 107
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:84907
Deposited By: Tony Diaz
Deposited On:21 Feb 2018 21:16
Last Modified:21 Feb 2018 21:16

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