A weakening Compton hump and soft X-ray excess detected in the Seyfert-1 galaxy MCG-02-58-22

Abstract

We have carried out an extensive X-ray spectral study of the bare Seyfert-1 galaxy MCG--02--58--22 to 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 ($\Gamma =1.80$) and luminosity ($L_{2-10\mathrm{keV}}=2.55\times 10^{44}$ erg/s). 2. The soft excess flux decreased by a factor of two in 2016, the Compton hump weakened/vanished in 2016, and the narrow FeK$\alpha$ emission line became marginally broad ($\sigma =0.35\pm 0.08$ keV) and its flux doubled in 2016. 3. From physical model fits we find that the normalization of the narrow component of the FeK$\alpha$ line 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 the reprocessed 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 clumpy torus 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 FeK$\alpha$ emission) and a polar component (producing the variable Compton hump), C. The reduction of the soft-excess flux by half and increase in the FeK$\alpha$ flux by a factor of two in the same period cannot be adequately explained by ionized disk reflection model alone.

Accepted for publication in ApJ

References in corpus (18)

• AGN Dusty Tori: I. Handling of Clumpy Media
• Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy
• The close environments of accreting massive black holes are shaped by radiative feedback
• Ionized outflows from active galactic nuclei as the essential elements of feedback
• AGN dust tori at low and high luminosities
• Multi-phase Nature of a Radiation-Driven Fountain with Nuclear Starburst in a Low-mass Active Galactic Nucleus
• A deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
• Resolving the soft X-ray ultra fast outflow in PDS 456
• The variable and non-variable X-ray absorbers in Compton-thin type-II Active Galactic Nuclei
• The narrow Fe K$\alpha$ line and the molecular torus in active galactic nuclei - an IR/X-ray view
• A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: I. X-ray spectral properties
• Geometrically thick obscuration by radiation-driven outflow from magnetized tori of active galactic nuclei
• The evolution of galaxies resolved in space and time: an inside-out growth view from the CALIFA survey
• Correlated X-ray/UV/optical variability and the nature of accretion disc in the bare Seyfert 1 galaxy Fairall~9
• On the disappearance of a cold molecular torus around the low-luminosity active galactic nucleus of NGC 1097
• A broadband X-ray spectral study of the Seyfert 1 galaxy ESO 141--G055 with XMM-Newton and NuSTAR
• An X-ray spectral study of the origin of reflection features in bare Seyfert 1 galaxy ESO 511--G030
• Investigating the origin of the Fe emission lines of the Seyfert 1 galaxy Mrk~205

Cited by in corpus (5)

• reXcor: A Model of the X-ray Spectrum of Active Galactic Nuclei that Combines Ionized Reflection and a Warm Corona
• The lively accretion disk in NGC 2992. II. The 2019/2021 X-ray monitoring campaigns
• The origin of the vanishing soft X-ray excess in the changing-look Active Galactic Nucleus Mrk 590
• Broadband spectral analysis of Mrk 926 using multi-epoch X-ray observations
• A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states