Diffuse X-Rays from the Inner 3 Parsecs of the Galaxy

Abstract

Recent observations with the Chandra X-ray Observatory have provided us with the capability to discriminate point sources, such as the supermassive black hole Sgr A*, from the diffuse emission within the inner 10'' of the Galaxy. The hot plasma producing the diffuse X-radiation, estimated at ~7.6*10^{31} ergs s^{-1} arcsec^{-2} in the 2-10 keV band, has a RMS electron density ~26 cm^{-3} and a temperature kT ~= 1.3 keV, with a total inferred mass of ~0.1 solar masses. At least some of this gas must be injected into the ISM via stellar winds. In the most recent census, about 25 bright, young stars have been identified as the dominant sources of the overall mass efflux from the Galactic center. In this paper, we use detailed 3-dimensional SPH simulations to study the wind-wind interactions occurring in the inner 3 parsecs of the Galaxy, with a goal of understanding what fraction, if any, of the diffuse X-ray flux measured by Chandra results from the ensuing shock heating of the ambient medium. We conclude that this process alone can account for the entire X-ray flux observed by Chandra in the inner 10'' of the Galaxy. Understanding the X-ray morphology of the environment surrounding Sgr A* will ultimately provide us with a greater precision in modeling the accretion of gas onto this object, which appears to be relatively underluminous compared to its brethren in the nuclei of other galaxies.

22 pages, 8 figures; new calculations reported, conclusion unchanged; accepted for publication in ApJ

References in corpus (6)

• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• The Supermassive Black Hole at the Galactic Center
• A Chandra Study of Sgr A East: A Supernova Remnant Regulating The Activity Of Our Galactic Center?
• Modeling Core-Collapse Supernovae in 3-Dimensions
• Hydrodynamical Accretion Onto Sgr A* From Distributed Point Sources
• Stellar Gas Flows Into A Dark Cluster Potential At The Galactic Center

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• Hydrodynamic Simulations of the Inner Accretion Flow of Sagittarius A* Fueled By Stellar Winds
• SNSPH: A Parallel 3-D Smoothed Particle Radiation Hydrodynamics Code
• Fifteen years of XMM-Newton and Chandra monitoring of Sgr A*: Evidence for a recent increase in the bright flaring rate
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• Spoon-Feeding Giant Stars to Supermassive Black Holes: Episodic Mass Transfer from Evolving Stars and Their Contribution to the Quiescent Activity of Galactic Nuclei
• Traces of past activity in the Galactic Centre
• Thermal X-Ray Iron Line Emission from the Galactic Center Black Hole Sagittarius A*
• Event-Horizon-Telescope Evidence for Alignment of the Black Hole in the Center of the Milky Way with the Inner Stellar Disk
• Accretion of cool stellar winds on Sgr A*: another puzzle of the Galactic Centre?
• Interstellar gas within $\sim 10$ pc of Sgr A${}^{\ast }$
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• Stochastic Acceleration in the Galactic Center HESS Source
• The pattern of accretion flow onto Sgr A*
• The X-ray Ridge Surrounding Sgr A* at the Galactic Center
• H3+ Spectroscopy and the Ionization Rate of Molecular Hydrogen in the Central Few Parsecs of the Galaxy
• Super stellar clusters with a bimodal hydrodynamic solution: an Approximate Analytic Approach
• A Possible Link Between the Galactic Center HESS Source and Sgr A*
• Diffuse X-rays from the Arches and Quintuplet clusters
• Ultra-High-Energy Cosmic Rays from the Radio Lobes of AGNs
• The Sgr B2 X-ray Echo of the Galactic Center Supernova Explosion that Produced Sgr A East
• The Influence of Gas Dynamics on Measuring the Properties of the Black Hole in the Center of the Milky Way with Stellar Orbits and Pulsars
• High Energy Cosmic-ray Diffusion in Molecular Clouds: A Numerical Approach
• Nonthermal THz to TeV Emission from Stellar Wind Shocks in the Galactic Center
• A Nonthermal Radio Filament Connected to the Galactic Black Hole?
• Accretion of Low Angular Momentum Material onto Black Holes: Radiation Properties of Axisymmetric MHD Flows
• XMM-Newton observations of the Galactic Centre Region - II: The soft thermal emission
• Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
• Multiple accretion events as a trigger for Sgr A* activity
• Diffusive Cosmic Ray Acceleration at the Galactic Centre
• Diffusive Cosmic-ray Acceleration in Sagittarius A*
• The Nature of Linearly Polarized Millimeter and Sub-millimeter Emission in Sagittarius A*
• Evolution of Supernova Remnants near the Galactic Center
• Assessing the Feasibility of Cosmic-Ray Acceleration by Magnetic Turbulence at the Galactic Center
• Probing the Density in the Galactic Center Region: Wind-Blown Bubbles and High-Energy Proton Constraints
• Can supernova shells feed supermassive black holes in galactic nuclei?
• The X-ray footprint of the CircumNuclear Disk
• Chandra X-ray Measurement of Gas-phase Heavy Element Abundances in the Central Parsec of the Galaxy
• Exploring High-Velocity NH_3(6,6) Emission at the Center of our Galaxy
• Radio Synchrotron Emission from Secondary Leptons in the Vicinity of Sgr A*
• Low angular momentum flow model of Sgr A* activity
• Decaying Sterile Neutrinos as a Heating Source in the Milky Way Center
• Hydrodynamic Evolution of Sgr A East: The Imprint of A Supernova Remnant in the Galactic Center
• A Bayesian chemical evolution model of the DustPedia Galaxy M74
• Low angular momentum accretion flow model of Sgr A* activity
• Compact stellar systems hosting an intermediate mass black hole: magnetohydrodynamic study of inflow-outflow dynamics
• Polarimetric Imaging of Sgr A* in its Flaring State
• High Energy Emission from the Galactic Center