The Close AGN Reference Survey (CARS). Mrk 1018 returns to the shadows after 30 years as a Seyfert 1
Letter
McElroy, R. E., Husemann, B., Croom, S., Davis, T.A., Bennert, V., Busch, G., Combes, F., Eckart, A., Pérez-Torres, M., Powell, M., Scharwächter, J., Tremblay, G.R. and Urrutia, T.. 2016. "The Close AGN Reference Survey (CARS). Mrk 1018 returns to the shadows after 30 years as a Seyfert 1." Astronomy and Astrophysics: a European journal. 593, p. L8. https://doi.org/10.1051/0004-6361/201629102
Article Title | The Close AGN Reference Survey (CARS). Mrk 1018 returns to the shadows after 30 years as a Seyfert 1 |
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ERA Journal ID | 1050 |
Article Category | Letter |
Authors | McElroy, R. E., Husemann, B., Croom, S., Davis, T.A., Bennert, V., Busch, G., Combes, F., Eckart, A., Pérez-Torres, M., Powell, M., Scharwächter, J., Tremblay, G.R. and Urrutia, T. |
Journal Title | Astronomy and Astrophysics: a European journal |
Journal Citation | 593, p. L8 |
Number of Pages | 4 |
Year | 2016 |
Publisher | EDP Sciences |
Place of Publication | France |
ISSN | 0004-6361 |
1432-0746 | |
Digital Object Identifier (DOI) | https://doi.org/10.1051/0004-6361/201629102 |
Web Address (URL) | https://www.aanda.org/articles/aa/full_html/2016/09/aa29102-16/aa29102-16.html |
Abstract | We report the discovery that the known "changing look" AGN Mrk 1018 has changed spectral type for a second time. New VLT-MUSE data taken in 2015 as part of the Close AGN Reference Survey (CARS) shows that the AGN has returned to its original Seyfert 1.9 classification. The CARS sample is selected to contain only bright type 1 AGN, but Mrk 1018's broad emission lines and continuum, typical of type 1 AGN, have almost entirely disappeared. We use spectral fitting of the MUSE spectrum and previously available spectra to determine the drop in broad line flux and the Balmer decrement. We find that the broad line flux has decreased by a factor of 4.75 ± 0.5 in Hα since an SDSS spectrum was taken in 2000. The Balmer decrement has not changed significantly implying no enhanced reddening with time, but the remaining broad lines are more asymmetric than those present in the type 1 phase. We posit that the change is due to an intrinsic drop in flux from the accretion disk rather than variable extinction or a tidal disruption event. |
Keywords | galaxies: Seyfert; galaxies: individual: Mrk 1018 |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510102. Astronomical instrumentation |
Byline Affiliations | University of Sydney |
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions, Australia | |
European Southern Observatory (ESO), Germany | |
Cardiff University, United Kingdom | |
California Polytechnic State University, United States | |
University of Cologne, Germany | |
Sorbonne University, France | |
Max Planck Institute for Radio Astronomy, Germany | |
Institute of Astrophysics of Andalusia, Spain | |
Yale University, United States | |
Gemini Observatory, United States | |
Leibniz Institute for Astrophysics Potsdam, Germany |
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https://research.usq.edu.au/item/z75x2/the-close-agn-reference-survey-cars-mrk-1018-returns-to-the-shadows-after-30-years-as-a-seyfert-1
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