@article{2ea9da874e1a4ca2b2e44ae2d3a157bb,
title = "PS1-13cbe: The rapid transition of a Seyfert 2 to a Seyfert 1",
abstract = "We present a nuclear transient event, PS1-13cbe, that was first discovered in the Pan-STARRS1 survey in 2013. The outburst occurred in the nucleus of the galaxy SDSS J222153.87+003054.2 at z = 0.123 55, which was classified as a Seyfert 2 in a pre-outburst archival Sloan Digital Sky Survey (SDSS) spectrum. PS1-13cbe showed the appearance of strong broad H α and H β emission lines and a non-stellar continuum in a Magellan spectrum taken 57 d after the peak of the outburst that resembled the characteristics of a Seyfert 1. These broad lines were not present in the SDSS spectrum taken a decade earlier and faded away within 2 yr, as observed in several late-time MDM spectra. We argue that the dramatic appearance and disappearance of the broad lines and a factor of ∼8 increase in the optical continuum are most likely caused by variability in the pre-existing accretion disc than a tidal disruption event, supernova, or variable obscuration. The time-scale for the turn-on of the optical emission of ∼70 d observed in this transient is among the shortest observed in a 'changing-look' active galactic nucleus.",
keywords = "accretion, accretion discs, black hole physics, galaxies: active, galaxies: nuclei",
author = "Reza Katebi and Ryan Chornock and Edo Berger and Jones, {David O.} and Ragnhild Lunnan and Raffaella Margutti and Armin Rest and Scolnic, {Daniel M.} and Burgett, {William S.} and Nick Kaiser and Kudritzki, {Rolf Peter} and Magnier, {Eugene A.} and Wainscoat, {Richard J.} and Christopher Waters",
note = "Funding Information: 1IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. Funding Information: We thank S. Gezari for useful comments. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, the Johns Hopkins University, Durham University, the University of Edinburgh, the Queen{\textquoteright}s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. Funding Information: Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbuka-gakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS website is http://www.sdss.org/. The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington. Publisher Copyright: {\textcopyright} 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.",
year = "2019",
month = aug,
day = "11",
doi = "10.1093/mnras/stz1552",
language = "English (US)",
volume = "487",
pages = "4057--4070",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "3",
}