The Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter $α

Abstract

A wealth of Galactic accreting X-ray binaries have been observed both in low/hard state and high/soft state. The transition between these two states was often detected. Observation shows that the transition luminosity between these two states is different for different sources, ranging from 1% to 4% of the Eddington luminosity. Even for the same source the transition luminosity at different outbursts is also different. The transition can occur from 0.0069 to 0.15 Eddington luminosity. To investigate the underlying physics, we study the influence of viscosity parameter $\alpha$ on the transition luminosity on the basis of the disk-corona model for black holes. We calculate the mass evaporation rate for a wide range of viscosity parameter, $0.1\le \alpha \le 0.9$. By fitting the numerical results, we obtain fitting formulae for both the transition accretion rate and the corresponding radius as a function of $\alpha$. We find that the transition luminosity is very sensitive to the value of $\alpha$, $L/L_{\mathrm{Edd}}\propto {\alpha }^{2.34}$. For $0.1\le \alpha \le 0.6$, the transition luminosity varies by two orders of magnitude, from 0.001 to 0.2 Eddington luminosity. Comparing with observations we find that the transition luminosity can be fitted by adjusting the value of $\alpha$, and the model determined values of $\alpha$ are mostly in the range of observationally inferred value. Meanwhile we investigate the truncation of the disk in the low/hard state for some luminous sources. Our results are roughly in agreement with the observations.

8 pages, 3 figures,accepted by PASJ

References in corpus (7)

• Accretion disc viscosity: how big is alpha?
• Vertical Structure of Gas Pressure-Dominated Accretion Disks with Local Dissipation of Turbulence and Radiative Transport
• The Existence of Inner Cool Disks in the Low Hard State of Accreting Black Holes
• INTEGRAL/RossiXTE high-energy observation of a state transition of GX 339-4
• X-ray spectral transitions of black holes from RXTE All-Sky Monitor
• Disk-Evaporation Fed Corona: Structure and Evaporation Feature with Magnetic Field
• The effect of heat conduction on the interaction of disk and corona around black holes

Cited by in corpus (35)

• The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• Accretion disks and coronae in the X-ray flashlight
• On the masses of OJ287 black holes
• A Model for the Correlation of Hard X-ray Index with Eddington Ratio in Black Hole X-ray Binaries
• Black Hole Binaries and Microquasars
• The hard to soft spectral transition in LMXBs - affected by recondensation of gas into an inner disk
• 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 origin of radio emission in broad absorption line quasars: Results from the LOFAR Two-metre Sky Survey
• Application of the Disk Evaporation Model to AGNs
• The mass fraction of AGN and the Fundamental Plane of black hole activity from a large X-ray selected sample of LINERs
• A disc corona-jet model for the radio/X-ray correlation in black hole X-ray binaries
• The Spectral Features of Disk and Corona with Mass Evaporation in the Low/Hard State
• A systematic study of the condensation of the corona and the application for ${\Gamma }_{2-10keV}-L_{\mathrm{bol}}/L_{\mathrm{Edd}}$ correlation in luminous active galactic nuclei
• Revisiting the structure and spectrum of the magnetic-reconnection-heated corona in luminous AGNs
• An Explanation for Overrepresentation of Tidal Disruption Events in Post-starburst Galaxies
• 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
• The disk evaporation model for the spectral features of low-luminosity active galactic nuclei
• Modelling the `outliers' track of the radio--X-ray correlation in X-ray binaries based on disc-corona model
• The Structure and Spectral Features of a Thin Disk and Evaporation-Fed Corona in High-Luminosity AGNs
• Hard and soft spectral states of ULXs
• Radiative Spectra from Disk Corona and Inner Hot Flow in Black Hole X-ray Binaries
• Analytical Model of Disk Evaporation and State Transitions in Accreting Black Holes
• Constraints on the Viscosity and Magnetic Field in Hot Accretion Flows around Black Holes
• Thermal X-ray iron line emission from the advection dominated accretion flow in the galactic binary GX 339-4
• A systematic study of the advection-dominated accretion flow for the origin of the X-ray emission in weakly magnetized low-level accreting neutron star
• Advection-dominated accretion flow for the varied transition luminosities in black hole X-ray binaries
• Hot accretion flow around neutron stars
• On the Maximal Value of the Turbulent alpha-Parameter in Accretion Discs
• Ionization structure and Fe K$\alpha$ energy for irradiated accretion disks
• Two-temperature radiative hot accretion flow around neutron stars
• Resistive Hot Accretion Flows with Anisotropic Pressure
• Effect of non-stationary accretion on spectral state transitions: An example of a persistent neutron star LMXB 4U 1636-536
• Systematic Analysis of Low/Hard State RXTE Spectra of GX 339-4 to Constrain the Geometry of the System
• X-ray constraint for the unseen companion of V723 Mon: it is a mass-gap black hole rather than binary neutron stars