The Man Behind the Curtain: X-rays Drive the Uv Through Nir Variability in the 2013 Active Galactic Nucleus Outburst in Ngc 2617
Year: 2014
Type: article
Abstract: After the All-Sky Automated Survey for SuperNovae discovered a significant brightening of the inner region of NGC 2617, we began a ∼70 day photometric and spectroscopic monitoring campaign from the X-ray through near-infrared (NIR) wavelengths. We report that NGC 2617 went through a dramatic outburst, during which its X-ray flux increased by over an order of magnitude followed by an increase of its optical/ultraviolet (UV) continuum flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8 galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical emission lines and a continuum blue bump. Such "changing look active galactic nuclei (AGNs)" are rare and provide us with important insights about AGN physics. Based on the Hβ line width and the radius–luminosity relation, we estimate the mass of central black hole (BH) to be (4 ± 1) × 10 7 M ☉ . When we cross-correlate the light curves, we find that the disk emission lags the X-rays, with the lag becoming longer as we move from the UV (2–3 days) to the NIR (6–9 days). Also, the NIR is more heavily temporally smoothed than the UV. This can largely be explained by a simple model of a thermally emitting thin disk around a BH of the estimated mass that is illuminated by the observed, variable X-ray fluxes.
Source: The Astrophysical Journal
Authors: B. J. Shappee, J. L. Prieto, D. Grupe, C. S. Kochanek, K. Z. Stanek, G. De Rosa, S. Mathur, Y. Zu, B. M. Peterson, R. W. Pogge, S. Komossa, M. Im, J. Jencson, T.W-S. Holoien, U. Basu, J. F. Beacom, D. M. Szczygieł, J. Brimacombe, S. Adams, A. Campillay, C. Choi, C. Contreras, M. Dietrich, M. Dubberley, M. Elphick, S. Foale, M. Giustini, C. Gonzalez, E. Hawkins, D. A. Howell, E. Y. Hsiao, M. Koss, K. M. Leighly, N. Morrell, D. Mudd, D. Mullins, J. M. Nugent, J. Parrent, M. M. Phillips, G. Pojmanski, W. Rosing, R. Ross, D. Sand, D. M. Terndrup, S. Valenti, Z. Walker, Y. Yoon
Institutions: The Ohio State University, Princeton University, Pennsylvania State University, Max Planck Institute for Radio Astronomy, Seoul National University, University of Warsaw, Las Campanas Observatory, Ohio University, Las Cumbres Observatory Global Telescope Network, European Space Agency, European Space Astronomy Centre, University of California, Santa Barbara, University of Hawaiʻi at Mānoa, University of Hawaii System, University of Oklahoma, Texas Tech University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Ohio State University, California Institute of Technology, National Research Foundation, Ministry of Science, ICT and Future Planning, National Research Foundation of Korea, Max-Planck-Gesellschaft, Jet Propulsion Laboratory, Center for Cosmology and Astroparticle Physics, Ohio State University, Science and Technology Facilities Council, Kavli Institute for Theoretical Physics, University of California, Santa Barbara
OpenAlex ID: W2950529756