Contributed Talk - Splinter TimeDomain

Wednesday, 15 September 2021, 15:18   (virtual TimeD)

Rebirth as a type 1.9 AGN: Optical Monitoring of the Changing-look AGN Mrk 1018

R. O'Rourke Brogan, M.Krumpe, G. Busch, A. Coil, F. Combes, S. Croom, T. Davis, J. Dexter, A. Eckhart, T. Granzer, D. Homan, B. Husemann, G. Lamer, G. Leung, M. Mallonn, R. McElroy, M. Pérez Torres, M. Powell, J. Scharwächter, M. Schramm, A. Schwope, G. Tremblay, T. Urrutia, H. Winkler
Leibniz-Institut für Astrophysik Potsdam, Potsdam, Center for Astrophysics and Space Sciences, University of California, San Diego, San Diego CA, Max-Planck-Institut für Astronomie, Heidelberg, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT, School of Physics & Astronomy, Cardiff University, Cardiff, Gemini Observatory, North Operations Center, Hilo, Max-Planck-Institut für extraterrestische Physik, Garching, I. Physikalisches Institut, Universität zu Köln, Köln, LERMA, Observatoire de Paris, College de France, PSL, CNRS, Sorbonne Univ., Paris, Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Canberra, Max-Planck-Institut für Radioastronomie, Bonn, Instituto de Astrofísica de Andalucía, Glorieta de las Astronomía s/n, Granada, The National Astronomical Observatory of Japan, Osawa, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa

Active galactic nuclei (AGN) should not be regarded as distinct astrophysical objects but as transient events in the life of a galaxy; a claim which supported by an increasing number of observed changing-look AGN. These objects change their spectral type with the appearance or disappearance of broad emission lines on time-scales as low as a few years. Mrk 1018 is one of such changing-look AGN and only the second known object to change spectral type twice after only 30 years. Extensive multi-wavelength data programs have followed up Mrk 1018’s behavior both during and after the transition phase. I will give a short summary of our main conclusions using these data. The primary focus will be on our ongoing long-term optical monitoring program of Mrk 1018 which studies the settling of the AGN into its new Seyfert type 1.9 phase. Over the last few years we have seen short outbursts and in 2020 we detected the most significant outburst since transition. These give a tentative indication of a periodic signal in the optical light curve of Mrk 1018. If confirmed, this would support a scenario in which Mrk 1018 might host a super-massive black hole binary - a clear breakthrough in understanding why Mrk 1018 changes its energy output repeatably and in such a drastic manner.