The condensation of the corona for the correlation between the hard X-ray photon index $\Gamma$ and the reflection scaling factor $\Re$ in active galactic nuclei

Abstract

Observationally, it is found that there is a strong correlation between the hard X-ray photon index $\Gamma$ and the Compton reflection scaling factor $\Re$ in active galactic nuclei. In this paper, we propose that the $\Gamma -\Re$ correlation can be explained within the framework of the condensation of the hot corona onto the cold accretion disc around a supermassive black hole. In the model, it is presumed that, initially, a vertically extended hot gas (corona) is supplied to the central supermassive black hole by capturing the interstellar medium and stellar wind. In this scenario, when the initial mass accretion rate $\dot{M}/{\dot{M}}_{\mathrm{Edd}}\gtrsim 0.01$, at a critical radius $r_{\mathrm{d}}$, part of the hot gas begins to condense onto the equatorial disc plane of the black hole, forming an inner cold accretion disc. Then the matter is accreted in the form of the disc-corona structure extending down to the innermost stable circular orbits of the black hole. The size of the inner disc is determined by the initial mass accretion rate. With the increase of the initial mass accretion rate, the size of the inner disc increases, which results in both the increase of the Compton reflection scaling factor $\Re$ and the increase of the hard X-ray photon index $\Gamma$. By comparing with a sample of Seyfert galaxies with well-fitted X-ray spectra, it is found that our model can roughly explain the observations. Finally, we discuss the possibility to apply our model to high mass X-ray binaries, which are believed to be fueled by the hot wind from the companion star.

arXiv commentAccepted for publication by MNRAS, 8 pages, 7 figures

References in corpus (51)

• Advection-Dominated Accretion: A Self-Similar Solution
• Advection-Dominated Accretion and the Spectral States of Black Hole X-Ray Binaries: Application to Nova Muscae 1991
• The disc instability model of dwarf-novae and low-mass X-ray binary transients
• Accretion disc viscosity: how big is alpha?
• Piecing Together the X-ray Background: Bolometric Corrections for Active Galactic Nuclei
• The Formation and Structure of a Strongly Magnetized Corona above Weakly Magnetized Accretion Disks
• Fluorescent iron lines as a probe of astrophysical black hole systems
• Simultaneous X-ray/optical/UV snapshots of active galactic nuclei from XMM-Newton: spectral energy distributions for the reverberation mapped sample
• The role of the reflection fraction in constraining black hole spin
• Correlation between Compton reflection and X-ray slope in Seyferts and X-ray binaries
• Local Study of Accretion Disks with a Strong Vertical Magnetic Field: Magnetorotational Instability and Disk Outflow
• XMM-Newton EPIC observations of 21 low-redshift PG quasars
• A global look at X-ray time lags in Seyfert Galaxies
• Global MHD Simulation of the Inner Accretion Disk in a Pseudo-Newtonian Potential
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• Vertical Structure of Gas Pressure-Dominated Accretion Disks with Local Dissipation of Turbulence and Radiative Transport
• Correlations between X-ray and radio spectral properties of accreting black holes
• ON THE GEOMETRY OF THE X-RAY EMITTING REGION IN SEYFERT GALAXIES
• The iron line in MCG-6-30-15 from XMM-Newton: evidence for gravitational light-bending?
• X-ray spectra of accretion discs with dynamic coronae
• Discovery of multiple Lorentzian components in the X-ray timing properties of the Narrow Line Seyfert 1 Ark 564
• Hot Disk Corona and Magnetic Turbulence in Radio-Quiet Active Galactic Nuclei: Observational Constraints
• Quasars and the Big Blue Bump
• Local outflows from turbulent accretion disks
• X-ray emission from black-hole binaries
• Two-temperature coronal flow above a thin disk
• The Existence of Inner Cool Disks in the Low Hard State of Accreting Black Holes
• An accretion disc-corona model for X-ray spectra of active galactic nuclei
• Frequency resolved spectroscopy of Cyg X-1: fast variability of the reflected emission in the soft state
• Broad-band spectra of Cyg X-1 and correlations between spectral characteristics
• Modelling spectral and timing properties of accreting black holes: the hybrid hot flow paradigm
• Re-condensation from an ADAF into an inner disk - the intermediate state of black hole accretion?
• Spectral analysis of the XMM-Newton data of GX 339-4 in the low/hard state: disc truncation and reflection
• Radiation Magneto-hydrodynamic Simulations of the Formation of Hot Accretion Disk Coronae
• A Model for the Correlation of Hard X-ray Index with Eddington Ratio in Black Hole X-ray Binaries
• A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies
• Reflection and noise in the low spectral state of GX339-4
• A self-consistent hybrid Comptonization model for broad-band spectra of accreting supermassive black holes
• Two Different Accretion Classes in Seyfert 1 Galaxies and QSOs
• Confirmation of a correlation between the X-ray luminosity and spectral slope of AGNs in the Chandra Deep Fields
• Extreme flux states of NGC 4151 observed with INTEGRAL
• The Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter $α
• Time lags in the ultraluminous X-ray source NGC 5408 X-1: implications for the black hole mass
• Disk corona interaction: mechanism for the disk truncation and spectrum change in low luminosity AGN
• The Emission from Inner Disk and Corona in the Low and Intermediate Spectral States of Black Hole X-ray Binaries
• The dust-eliminated shape of quasar spectra in the near-infrared: a hidden part of the big blue bump
• The Spectral Features of Disk and Corona with Mass Evaporation in the Low/Hard State
• The effect of disk magnetic fields on the truncation of geometrically thin disks in AGN
• The disk evaporation model for the spectral features of low-luminosity active galactic nuclei
• The Structure and Spectral Features of a Thin Disk and Evaporation-Fed Corona in High-Luminosity AGNs
• Coronae above accretion disks around black holes: The effect of Compton cooling

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• Correlation between relativistic reflection fraction and photon index in NuSTAR sample of Seyfert 1 AGN
• Peculiar disk behaviors of the black hole candidate MAXI J1348-630 in the hard state observed by Insight-HXMT and Swift
• Analytical Model of Disk Evaporation and State Transitions in Accreting Black Holes
• Centrally Concentrated X-ray Radiation from an Extended Accreting Corona in Active Galactic Nuclei
• The peculiar spectral evolution of the new X-ray transient MAXI J0637-430
• X-ray spectral correlations in a sample of Low-mass black hole X-ray binaries in the hard state
• Reflare in MAXI J1348-630]{Evolution of disc and corona in MAXI J1348-630 during the 2019 reflare: NICER and Insight-HXMT view
• A Model for Spectral States and Their Transition in Cyg X-1
• Our Supermassive Black Hole Rivaled the Sun in the Ancient X-ray Sky
• Advection-dominated accretion flow for the varied transition luminosities in black hole X-ray binaries
• Accretion flows in the hard state of black hole X-ray binaries: the effect of hot gas condensation
• Correlated variability of the reflection fraction with the X-ray flux and spectral index for Mkn 478
• A Population Study for Searching Supermassive Binary Black Holes in Active Galactic Nuclei: Continuum Spectral Features and Periodic Variabilities