Turner, TJ and Reeves, JN and Braito, V and Costa, M (2018) On the nature of the high-energy rollover in 1H 0419-577. Monthly Notices of the Royal Astronomical Society, 476 (1). 1258 -1270. ISSN 1365-2966

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Abstract

A NuSTAR/Swift observation of the luminous Seyfert 1 galaxy 1H 0419-577 taken during 2015 reveals one of the most extreme high-energy cut-offs observed to date from an AGN – an origin due to thermal Comptonization would imply a remarkably low coronal temperature kT ∼ 15 keV. The low-energy peak of the spectrum in the hard X-ray NuSTAR band, which peaks before the expected onset of a Compton hump, rules out strong reflection as the origin of the hard excess in this AGN. We show the origin of the high-energy rollover is likely due to a combination of both thermal Comptonization and an intrinsically steeper continuum, which is modified by absorption at lower energies. Furthermore, modelling the broad-band XUV continuum shape as a colour-corrected accretion disc, requires the presence of a variable warm absorber to explain all flux and spectral states of the source, consistent with the previous work on this AGN. While absorber variations produce marked spectral variability in this AGN, consideration of all flux states allows us to isolate a colourless component of variability that may arise from changes in the inner accretion flow, typically at around 10 rg.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: galaxies, active - quasars, individual, 1H 0419-577, Seyfert, X-rays
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Related URLs:
Depositing User: Symplectic
Date Deposited: 02 May 2018 08:36
Last Modified: 02 May 2018 08:44
URI: http://eprints.keele.ac.uk/id/eprint/4814

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