New Spectral State of Supercritical Accretion Flow with Comptonizing Outflow

Abstract

Supercritical accretion flows inevitably produce radiation-pressure driven outflows, which will Compton up-scatter soft photons from the underlying accretion flow, thereby making hard emission. We perform two dimensional radiation hydrodynamic simulations of supercritical accretion flows and outflows, incorporating such Compton scattering effects, and demonstrate that there appears a new hard spectral state at higher photon luminosities than that of the slim-disk state. In this state, as the photon luminosity increases, the photon index decreases and the fraction of the hard emission increases. The Compton $y$-parameter is of the order of unity (and thus the photon index will be $\sim 2$) when the apparent photon luminosity is $\sim 30L_{\mathrm{E}}$ (with $L_{\mathrm{E}}$ being the Eddington luminosity) for nearly face-on sources. This explains the observed spectral hardening of the ULX NGC1313 X-2 in its brightening phase and thus supports the model of supercritical accretion onto stellar mass black holes in this ULX.

15 pages, 4 figures, accepted for publication in PASJ

References in corpus (8)

• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• Global Radiation-Magnetohydrodynamic Simulations of Black Hole Accretion Flow and Outflow: Unified Model of Three States
• Why Is Supercritical Disk Accretion Feasible?
• Testing the Paradigm that Ultraluminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes
• Chandra monitoring observations of the ultraluminous X-ray source NGC 5204 X-1
• A Stellar-mass Black Hole in the Ultra-luminous X-ray Source M82 X-1?
• A photon breeding mechanism for the high-energy emission of relativistic jets
• Spectral energy distribution of super-Eddington flows

Cited by in corpus (30)

• Global Structure of Three Distinct Accretion Flows and Outflows around Black Holes through Two-Dimensional Radiation-Magnetohydrodynamic Simulations
• Ultraluminous X-ray Sources in the Chandra and XMM-Newton Era
• Global simulations of axisymmetric radiative black hole accretion disks in general relativity with a sub-grid magnetic dynamo
• Clumpy Outflow from Supercritical Accretion Flows
• Formation of Overheated Regions and Truncated Disks around Black Holes; Three-dimensional General Relativistic Radiation-magnetohydrodynamics Simulations
• Spectra of Black Hole Accretion Models of Ultra-Luminous X-ray Sources
• Three-dimensional structure of clumpy outflow from supercritical accretion flow onto black holes
• X-ray spectral variability in the ultraluminous X-ray source Holmberg IX X-1
• Photon-conserving Comptonization in simulations of accretion disks around black holes
• Hyper-Eddington accretion flows onto black holes accompanied by powerful outflows
• A radiation-hydrodynamic model of accretion columns for ultra-luminous X-ray pulsars
• Systematic two-dimensional radiation hydrodynamic simulations of super-Eddington accretion flow and outflow: Comparison with the slim disk model
• Radiation hydrodynamics simulations of wide-angle outflows from super-critical accretion disks around black holes
• A broadband X-ray spectral study of the intermediate-mass black hole candidate M82 X-1 with NuSTAR, Chandra and Swift
• Probing the Peculiar Behavior of GRS 1915+105 at Near-Eddington Luminosity
• Theoretical modeling of Comptonized X-ray spectra of super-Eddington accretion flow: origin of hard excess in Ultraluminous X-Ray Sources
• Large-scale outflow structure and radiation properties of super-Eddington flow: Dependence on the accretion rates
• Super-Eddington growth of black holes in the early Universe: effects of disk radiation spectra
• Global Three-Dimensional Radiation Magnetohydrodynamic Simulations of Accretion onto a Stellar Mass Black Hole at Sub- and Near-critical Accretion Rates
• Systematic Broad-band X-ray Study of super-Eddington Accretion onto Supermassive Black Holes. I. X-ray Continuum
• Continuous Jets and Backflow Models for the Formation of W50/SS433 in Magnetohydrodynamics Simulations
• Magneto-hydrodynamic Simulations of a Jet Drilling an HI Cloud: Shock Induced Formation of Molecular Clouds and Jet Breakup
• Suzaku investigation into the nature of the nearest ultraluminous X-ray source, M33 X-8
• Two-dimensional Inflow-outflow Solution of Supercritical Accretion Flow
• Two Power-Law States of the Ultraluminous X-ray Source IC342 X-1
• Random walks and effective optical depth in relativistic flow
• What Determines Unique Spectra of Super-Eddington Accretors?: Origin of Optically Thick and Low Temperature Coronae in Super-Eddington Accretion Flows
• Structure of the super-Eddington outflow and itsimpact on the cosmological scale
• Recurrent Outbursts and Jet Ejections Expected in Swift J1644+57: Limit-Cycle Activities in a Supermassive Black Hole
• The extreme properties of the nearby hyper-Eddington accreting Active Galactic Nucleus in IRAS 04416+1215