The Close AGN Reference Survey (CARS) - What is causing Mrk1018's return to the shadows after 30 years?

Abstract

We recently discovered that the active galactic nucleus (AGN) of Mrk 1018 has changed optical type again after 30 years as a type 1 AGN. Here we combine Chandra, NuStar, Swift, Hubble Space Telescope and ground-based observations to explore the cause of this change. The 2-10keV flux declines by a factor of ~8 between 2010 and 2016. We show with our X-ray observation that this is not caused by varying neutral hydrogen absorption along the line-of-sight up to the Compton-thick level. The optical-UV spectral energy distributions are well fit with a standard geometrically thin optically thick accretion disc model that seems to obey the expected $L\sim T^4$ relation. It confirms that a decline in accretion disc luminosity is the primary origin for the type change. We detect a new narrow-line absorber in Lya blue-shifted by ~700km/s with respect to the systemic velocity of the galaxy. This new Lya absorber could be evidence for the onset of an outflow or a companion black hole with associated gas that could be related to the accretion rate change. However, the low column density of the absorber means that it is not the direct cause for Mrk 1018's changing-look nature.

4 pages, 4 figures, Published in A&A

References in corpus (6)

• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• Quasar Accretion Disks Are Strongly Inhomogeneous
• Testing Accretion Disk Theory in Black Hole X-ray Binaries
• AGN Type-casting: Mrk 590 No Longer Fits the Role
• The Close AGN Reference Survey (CARS) - Mrk 1018 returns to the shadows after 30 years as a Seyfert 1
• Rapid N_H changes in NGC 4151

Cited by in corpus (26)

• iPTF Discovery of the Rapid "Turn On" of a Luminous Quasar
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• Magnetic flux inversion in a peculiar changing look AGN
• Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
• BASS XXXIX: Swift-BAT AGN with changing-look optical spectra
• The Close AGN Reference Survey (CARS): IFU survey data and the BH mass dependence of long-term AGN variability
• Probing the Origin of Changing-look Quasar Transitions with Chandra
• Two New "Turn-off" Changing-look Active Galactic nuclei and Implication on "Partially Obscured" AGNs
• A magnetic accretion disk-outflow model for changing look active galactic nuclei
• MUSE observations of a changing-look AGN I: The re-appearance of the broad emission lines
• WISE view of changing-look AGNs: evidence for a transitional stage of AGNs
• The Close AGN Reference Survey (CARS): Mrk 1018 halts dimming and experiences strong short-term variability
• Long-term and multi-wavelength evolution of a changing-look AGN Mrk 1018
• Improving the selection of changing-look AGNs through multi-wavelength photometric variability
• Joint NuSTAR and Chandra analysis of the obscured quasar in IC 2497 - Hanny's Voorwerp system
• Spectropolarimetry of the changing-look active galactic nucleus Mrk 1018
• The outburst of the changing-look AGN IRAS23226-3843 in 2019
• The origin of the vanishing soft X-ray excess in the changing-look Active Galactic Nucleus Mrk 590
• Still alive and kicking: A significant outburst in changing-look AGN Mrk 1018
• Changing-Look Inspirals: Trends and Switches in AGN Disk Emission as Signposts for Merging Black Hole Binaries
• Flaires: A Comprehensive Catalog of Dust-Echo-like Infrared Flares
• A VLBI Proper Motion Analysis of the Recoiling Supermassive Black Hole Candidate Mrk 1018
• The relation between quasars' optical spectra and variability
• A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states