On the Nature of the High-Energy Rollover in 1H 0419-577

Thumbnail Image

Files

Turner1802.00795.pdf (1.2 MB)

Links to Files

https://arxiv.org/pdf/1802.00795.pdf

Permanent Link

http://hdl.handle.net/11603/7799

Collections

UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)
UMBC Faculty Collection
UMBC Physics Department

Author/Creator

Author/Creator ORCID

Date

2018

Type of Work

journal articles
Text

Department

Program

Citation of Original Publication

Monthly Notices of the Royal Astronomical Society

Rights

This item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please contact the author.

Subjects

NuSTAR/Swift observation
galaxies
1H 0419-577
Seyfert galaxy

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 a intrinsically steeper continuum, which is modified by absorption at lower energies. Furthermore, modeling the broadband 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.