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A Weakening Compton Hump and Soft X-ray Excess Detected in the Seyfert-1 Galaxy MCG –02–58–22We have carried out an extensive X-ray spectral study of the bare Seyfert-1 galaxy MCG –02–58–22to ascertain the nature of the X-ray reprocessing media, using observations from Suzaku(2009) and simultaneous observations from XMM-Newton and NuSTAR(2016) . The most significant results of our investigation are: 1. The primary X-ray emission from the corona is constant in these observations, both in terms of the power law slope (Γ = 1.80) and luminosity (L2−10 keV= 2.55×1044erg s−1). 2.The soft excess flux decreased by a factor of two in 2016, the Compton hump weakened/vanished in2016, and the narrow FeKαemission line became marginally broad (σ= 0.35±0.08 keV) and its flux doubled in 2016. 3. From physical model fits we find that the normalization of the narrow component of the FeKαline does not change in the two epochs, although the Compton hump vanishes in the same time span. Since the primary X-ray continuum does not change, we presume that any changes in there processed emission must arise due to changes in the reprocessing media. Our primary conclusions are: A. The vanishing of the Compton hump in 2016 can probably be explained by a dynamic clumpytorus which is infalling/outflowing, or by a polar torus wind. B. The torus in this AGN possibly has two structures: an equatorial toroidal disk (producing the narrow FeKαemission) and a polar component(producing the variable Compton hump), C. The reduction of the soft-excess flux by half and increase in the FeKαflux by a factor of two in the same period cannot be adequately explained by ionized disk reflection model alone.
Document ID
20210015852
Acquisition Source
Goddard Space Flight Center
Document Type
Accepted Manuscript (Version with final changes)
Authors
Sibasish Laha ORCID
(University of Maryland, Baltimore County Baltimore, Maryland, United States)
Ritesh Ghosh ORCID
(Visva-Bharati University Shānti Niketan, West Bengal, India)
Date Acquired
May 19, 2021
Publication Date
July 12, 2021
Publication Information
Publication: Astrophysical Journal
Publisher: IOP Publishing
Volume: 915
Issue: 2
Issue Publication Date: July 12, 2021
ISSN: 0004-637X
e-ISSN: 1538-4357
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: 80GSFC21M0002
Distribution Limits
Public
Copyright
Portions of document may include copyright protected material.
Technical Review
External Peer Committee
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