@article{5a809e7e8d6e49c59d4a2d1e1d8186b9,
title = "Now you see it, now you don't: The disappearing central engine of the quasar J1011+5442",
abstract = "We report the discovery of a new 'changing-look' quasar, SDSS J101152.98+544206.4, through repeat spectroscopy from the Time Domain Spectroscopic Survey. This is an addition to a small but growing set of quasars whose blue continua and broad optical emission lines have been observed to decline by a large factor on a time-scale of approximately a decade. The 5100 {\AA} monochromatic continuum luminosity of this quasar drops by a factor of >9.8 in a rest-frame time interval of <9.7 yr, while the broad Hα luminosity drops by a factor of 55 in the same amount of time. The width of the broad Hα line increases in the dim state such that the black hole mass derived from the appropriate single-epoch scaling relation agrees between the two epochs within a factor of 3. The fluxes of the narrow emission lines do not appear to change between epochs. The light curve obtained by the Catalina Sky Survey suggests that the transition occurs within a rest-frame time interval of approximately 500 d. We examine three possible mechanisms for this transition suggested in the recent literature. An abrupt change in the reddening towards the central engine is disfavoured by the substantial difference between the time-scale to obscure the central engine and the observed time-scale of the transition. A decaying tidal disruption flare is consistent with the decay rate of the light curve but not with the prolonged bright state preceding the decay; nor can this scenario provide the power required by the luminosities of the emission lines. An abrupt drop in the accretion rate on to the supermassive black hole appears to be the most plausible explanation for the rapid dimming.",
author = "Runnoe, {Jessie C.} and Sabrina Cales and Ruan, {John J.} and Michael Eracleous and Anderson, {Scott F.} and Yue Shen and Green, {Paul J.} and Eric Morganson and Stephanie LaMassa and Greene, {Jenny E.} and Tom Dwelly and Schneider, {Donald P.} and Andrea Merloni and Antonis Georgakakis and A. Roman-Lopes",
note = "Funding Information: Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS web site is www.sdss.org. Funding Information: The LINEAR program is funded by the National Aeronautics and Space Administration at MIT Lincoln Laboratory under Air Force Contract FA8721-05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government. Funding Information: The CSS survey is funded by the National Aeronautics and Space Administration under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. The CRTS survey is supported by the US National Science Foundation under grants AST-0909182. Funding Information: We thank the referee, Benjamin Shappee, for helpful comments and suggestions. ARL acknowledges partial financial support from the DIULS Regular project PR15143. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS web site is www.sdss.org. SDSS-IV is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration including the Brazilian Participation Group, Carnegie Institution for Science, Carnegie Mellon University, the Chilean Participation Group, Harvard-Smithsonian Center for Astrophysics, Instituto de Astrof{\'i}sica de Canarias, The Johns Hopkins University, Kavli Institute for the Physics and Mathematics of the Universe (IPMU) / University of Tokyo, Lawrence Berkeley National Laboratory, Leibniz Institut fr Astrophysik Potsdam (AIP), Max-Planck-Institut fr Astrophysik (MPA, Garching), Max-Planck-Institut fr Extraterrestrische Physik (MPE), Max-Planck-Institut fr Astronomie (MPIA, Heidelberg), National Astronomical Observatory of China, New Mexico State University, New York University, University of Notre Dame, Observatrio Nacional do Brasil, The Ohio State University, Pennsylvania State University, Shanghai Astronomical Observatory, United Kingdom Participation Group, Universidad Nacional Autnoma de M{\'e}xico, University of Arizona, University of Colorado Boulder, University of Portsmouth, University of Utah, University of Washington, University of Wisconsin, Vanderbilt University, and Yale University. The CSS survey is funded by the National Aeronautics and Space Administration under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. The CRTS survey is supported by the US National Science Foundation under grants AST-0909182. The LINEAR program is funded by the National Aeronautics and Space Administration at MIT Lincoln Laboratory under Air Force Contract FA8721- 05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. Funding Information: We thank the referee, Benjamin Shappee, for helpful comments and suggestions. ARL acknowledges partial financial support from the DIULS Regular project PR15143. Funding Information: This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. Publisher Copyright: {\textcopyright} 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society",
year = "2020",
month = jan,
day = "1",
doi = "10.1093/mnras/stv2385",
language = "English (US)",
volume = "455",
pages = "1691--1701",
journal = "Monthly Notices of the Royal Astronomical Society: Letters",
issn = "1745-3925",
publisher = "Oxford University Press",
number = "2",
}