A Generalised Bondi Accretion Model for the Galactic Centre

Abstract

We develop an analytic, steady-state model for the gas environment in quiescent galactic nuclei. We assume that the mass is constantly supplied by a spherically symmetric distribution of wind emitting stars, and that gravity is solely due to a central supermassive black hole. We show that at some finite radius, where the Keplerian velocity is comparable to the wind velocity, the bulk velocity vanishes. Matter generated below that radius will be accreted onto the black hole, while matter outside it will escape the system. Under certain conditions, the flow may become supersonic at both domains. We obtain radial profiles of the hydrodynamic variables and verify them using a time-dependent hydrodynamic simulation. We delineate the conditions under which radiative cooling can be neglected, and predict the luminosity and spectrum of the free-free X-ray emission from such a system. We discuss applications of our solution to our own Galactic Centre and other quiescent galactic nuclei.

References in corpus (25)

• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• The Birth of a Relativistic Outflow in the Unusual γ-ray Transient Swift J164449.3+573451
• Thermal Instability in Gravitationally-Stratified Plasmas: Implications for Multi-Phase Structure in Clusters and Galaxy Halos
• Radiatively Inefficient Accretion in Nearby Galaxies
• Tidal Disruption Events Prefer Unusual Host Galaxies
• Discovery of an outflow from radio observations of the tidal disruption event ASASSN-14li
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• A Dynamical Model for Hot Gas in the Galactic Center
• ASASSN-14li: A Model Tidal Disruption Event
• Quantifying Supernovae-Driven Multiphase Galactic Outflows
• Hydrodynamic Simulations of the Inner Accretion Flow of Sagittarius A* Fueled By Stellar Winds
• The dynamics, appearance and demographics of relativistic jets triggered by tidal disruption of stars in quiescent supermassive black holes
• Computational aspects of astrophysical MHD and turbulence
• Inflow-Outflow Model with Conduction and Self-Consistent Feeding for Sgr A*
• An enhanced rate of tidal disruptions in the centrally overdense E+A galaxy NGC 3156
• The Delay Time Distribution of Tidal Disruption Flares
• Low density, radiatively inefficient rotating-accretion flow onto a black hole
• The X-ray Ridge Surrounding Sgr A* at the Galactic Center
• Towards Self-Consistent Modelling of the Sgr A* Accretion Flow: Linking Theory and Observation
• Practical flux-prescriptions for gamma-ray burst afterglows, from early to late times
• Circumnuclear Media of Quiescent Supermassive Black Holes
• Modeling Hot Gas Flow in the Low-Luminosity Active Galactic Nucleus of NGC3115

Cited by in corpus (6)

• On the charge of the Galactic centre black hole
• Precession-induced Variability in AGN Jets and OJ 287
• Near-infrared observations of star formation and gas flows in the NUGA galaxy NGC 1365
• Dust Echoes from Luminous Fast Blue Optical Transients
• Black-hole activity feedback across vast scales
• Global structure and dynamics of slowly rotating accretion flows