Evolution of a Relativistic Outflow and X-Ray Corona in the Extreme Changing-look AGN 1ES 1927+654
Masterson M, Kara E, Ricci C, Garcia J, Fabian AC, Pinto C, Kosec P, Remillard RA, Loewenstein M, Trakhtenbrot B, Arcavi I (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Book Volume: 934
Journal Issue: 1
Abstract
1ES 1927+654 is a paradigm-defying active galactic nucleus (AGN) and one of the most peculiar X-ray nuclear transients. In early 2018, this well-known AGN underwent a changing-look event, in which broad optical emission lines appeared and the optical flux increased. Yet, by 2018 July, the X-ray flux had dropped by over two orders of magnitude, indicating a dramatic change in the inner accretion flow. With three years of observations with NICER, XMM-Newton, and NuSTAR, we present the X-ray evolution of 1ES 1927+654, which can be broken down into three phases: (1) an early super-Eddington phase with rapid variability in X-ray luminosity and spectral parameters, (2) a stable super-Eddington phase at the peak X-ray luminosity, and (3) a steady decline back to the pre-outburst luminosity and spectral parameters. For the first time, we witnessed the formation of the X-ray corona, as the X-ray spectrum transitioned from thermally dominated to primarily Comptonized. We also track the evolution of the prominent, broad 1 keV feature in the early X-ray spectra and show that this feature can be modeled with blueshifted reflection (z = -0.33) from a single-temperature blackbody irradiating spectrum using xillverTDE, a new flavor of the xillver models. Thus, we propose that the 1 keV feature could arise from reflected emission off the base of an optically thick outflow from a geometrically thick, super-Eddington inner accretion flow, connecting the inner accretion flow with outflows launched during extreme accretion events (e.g., tidal disruption events). Lastly, we compare 1ES 1927+654 to other nuclear transients and discuss applications of xillverTDE to super-Eddington accretors.
Authors with CRIS profile
Involved external institutions
Tel Aviv University
Israel (IL)
Massachusetts Institute of Technology (MIT)
United States (USA) (US)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
Institute of Space Astrophysics and Cosmic Physics / Palermo Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF)
Italy (IT)
University of Cambridge
United Kingdom (GB)
Diego Portales University / Universidad Diego Portales
Chile (CL)
Israel (IL)
Massachusetts Institute of Technology (MIT)
United States (USA) (US)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
Institute of Space Astrophysics and Cosmic Physics / Palermo Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF)
Italy (IT)
University of Cambridge
United Kingdom (GB)
Diego Portales University / Universidad Diego Portales
Chile (CL)
How to cite
APA:
Masterson, M., Kara, E., Ricci, C., Garcia, J., Fabian, A.C., Pinto, C.,... Arcavi, I. (2022). Evolution of a Relativistic Outflow and X-Ray Corona in the Extreme Changing-look AGN 1ES 1927+654. Astrophysical Journal, 934(1). https://dx.doi.org/10.3847/1538-4357/ac76c0
MLA:
Masterson, Megan, et al. "Evolution of a Relativistic Outflow and X-Ray Corona in the Extreme Changing-look AGN 1ES 1927+654." Astrophysical Journal 934.1 (2022).
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