The pattern of accretion flow onto Sgr A*
arXiv:astro-ph/0604516 · doi:10.1111/j.1365-2966.2006.10470.x
Abstract
The material accreting onto Sgr A* most probably comes from the nearby stars. We analyze the pattern of this flow at distances of a fraction of a parsec and we argue that the net angular momentum of this material is low but non-negligible, and the initially supersonic disk accretion changes into subsonic flow with constant angular momentum. Next we estimate the flow parameters at a distance from the black hole and we argue that for the plausible parameter range the accretion flow is non-stationary. The inflow becomes supersonic at distance of but the solution does not continue below the horizon and the material piles up forming a torus, or a ring, at a distance of a few up to tens of Schwarzchild radii. Such a torus is known to be unstable and may explain strong variability of the flow in Sgr A*. Our considerations show that the temporary formation of such a torus seems to be unavoidable. Our best fitting model predicts a rather large accretion rate of around directly on Sgr A*. We argue that magnetic fields in the flow are tangled and this allows our model to overcome the disagreement with the Faraday rotation limits.
10 pages,7 figures, accepted to MNRAS, references added to section 3.5 and to bibliography
References in corpus (19)
- Diffuse X-ray Emission in a Deep Chandra Image of the Galactic Center
- On The Nature of the Variable Infrared Emission from Sgr A*
- First Simultaneous NIR/X-ray Detection of a Flare from SgrA*
- Galactic Centre stellar winds and Sgr A* accretion
- Hard X-ray view of the past activity of Sgr A* in a natural Compton mirror
- The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared
- The Flare Activity of SgrA*; New Coordinated mm to X-Ray Observations
- A fresh look at the unstable simulations of Bondi-Hoyle-Lyttleton accretion
- Electron Acceleration around the Supermassive Black Hole at the Galactic Center
- Properties of Accretion Shock Waves in Viscous Flows Around Black Holes
- Variable Linear Polarization from Sagittarius A*: Evidence for a Hot Turbulent Accretion Flow
- A Possible Rossby Wave Instability Origin for the Flares in Sagittarius A*
- Accretion of cool stellar winds on Sgr A*: another puzzle of the Galactic Centre?
- Stochastic Electron Acceleration During the NIR and X-ray Flares in Sagittarius A*
- Repeated X-ray Flaring Activity in Sagittarius A*
- Dependence of General Relativistic Accretion on Black Hole Spin
- Radiative Shocks in Rotating Accretion Flows around Black Holes
- Spin-Induced Disk Precession in Sagittarius A*
- Long-Term Radio Modulation in Sagittarius A* from Spin-Induced Disk Precession
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- Variable accretion and emission from the stellar winds in the Galactic centre
- Inflow-Outflow Model with Conduction and Self-Consistent Feeding for Sgr A*
- K-band polarimetry of an Sgr A* flare with a clear sub-flare structure
- Three-Dimensional Moving-Mesh Simulations of Galactic Center Cloud G2
- Black-Hole Accretion Disc as an Analogue Gravity Model
- Shocks in the relativistic transonic accretion with low angular momentum
- Oscillating shocks in the low angular momentum flows as a source of variability of accreting black holes
- Hysteresis effects and diagnostics of the shock formation in low angular momentum axisymmetric accretion in the Kerr metric
- Unstable mass-outflows in geometrically thick accretion flows around black holes
- A Possible Model for the Long-Term Flares of Sgr A*
- On the development of the Papaloizou-Pringle instability of the black hole-torus systems and quasi-periodic oscillations
- Alive but Barely Kicking: News from 3+ years of Swift and XMM-Newton X-ray Monitoring of Quasi-Periodic Eruptions from eRO-QPE1
- Colliding Winds in and around the Stellar Group IRS 13E at the Galactic Center
- Accretion of Low Angular Momentum Material onto Black Holes: Radiation Properties of Axisymmetric MHD Flows
- General relativistic hydrodynamic simulations of perturbed transonic accretion
- Nonaxisymmetric Effects in the Black Hole Accretion Inviscid Hydrodynamics: Formation and Evolution of a Tilted Torus
- Low angular momentum flow model for Sgr A*
- Gamma-ray emission from proton-proton interactions in hot accretion flows
- Multiple accretion events as a trigger for Sgr A* activity
- Spherically Symmetric Accretion Flows: Minimal Model with MHD Turbulence
- Perturbation of mass accretion rate, associated acoustic geometry and stability analysis
- Low angular momentum flow model II for Sgr A*
- Relativistic sonic geometry for isothermal accretion in the Schwarzschild metric
- Accretion in active galactic nuclei and disk-jet coupling
- Black Hole spin dependence of general relativistic multi-transonic accretion close to the horizon
- Radiative shock oscillation model for the long-term flares of Sgr A*
- Linear perturbations of low angular momentum accretion flow in the Kerr metric and the corresponding emergent gravity phenomena
- Acoustic geometry obtained through the perturbation of the Bernoulli's constant
- Thermally Driven Winds from Radiatively Inefficient Accretion Flows
- Relativistic sonic geometry for isothermal accretion in the Kerr metric
- Effects of resistivity on standing shocks in low angular momentum flows around black holes
- Influence of flow thickness on general relativistic low angular momentum accretion around spinning black holes
- Low angular momentum flow model of Sgr A* activity
- On the efficiency of the Blandford-Znajek mechanism for low angular momentum relativistic accretion
- Effect of matter geometry on low angular momentum black hole accretion in the Kerr metric
- Influence of matter geometry on shocked flows-I: Accretion in the Schwarzschild metric
- Dynamical analogue spacetimes in non-relativistic flows
- Low angular momentum accretion flow model of Sgr A* activity
- SgrA* emission at 7mm: variability and periodicity
- M31 nucleus: molecular and ionised gas content upper limits
- On the origin of core radio emissions from black hole sources in the realm of relativistic shocked accretion flow