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Related papers: Hydrodynamical Accretion Onto Sgr A* From Distribu…

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Radiatively inefficient accretion flow models have been shown to accurately account for the spectrum and luminosity observed from Sgr A* in the X-ray regime down to mm wavelengths. However, observations at a few GHz cannot be explained by…

High Energy Astrophysical Phenomena · Physics 2017-07-19 Ian Christie , Maria Petropoulou , Petar Mimica , Dimitrios Giannios

We present hydrodynamic simulations of the inner few parsecs of the Milky Way's Galactic Center that, for the first time, combine a realistic treatment of stellar winds and the circumnuclear disk as they interact with the gravitational…

High Energy Astrophysical Phenomena · Physics 2023-08-09 Siddhant Solanki , Sean M. Ressler , Lena Murchikova , James M. Stone , Mark R. Morris

Proposed scaling relations of a characteristic timescale in the X-ray power spectral density of galactic and supermassive black holes have been used to argue that the accretion process is the same for small and large black holes. Here, we…

Astrophysics of Galaxies · Physics 2009-11-13 L. Meyer , T. Do , A. Ghez , M. R. Morris , S. Yelda , R. Schoedel , A. Eckart

The center of the Milky Way hosts a massive black hole. The observational evidence for its existence is overwhelming. The compact radio source Sgr A* has been associated with a black hole since its discovery. In the last decade,…

Astrophysics of Galaxies · Physics 2010-02-08 S. Gillessen , F. Eisenhauer , H. Bartko , K. Dodds-Eden , T. K. Fritz , O. Pfuhl , T. Ott , R. Genzel

The supermassive black hole in the center of the Milky Way, Sgr A*, displays a nearly flat radio spectrum that is typical for jets in active galactic nuclei. Indeed, time-dependent magnetized models of radiatively inefficient accretion…

High Energy Astrophysical Phenomena · Physics 2015-06-17 M. Moscibrodzka , H Falcke

The recent detection of a gamma-ray flux from the direction of the Galactic center by EGRET on the Compton GRO raises the question of whether this is a point source (possibly coincident with the massive black hole candidate Sgr A*) or a…

Astrophysics · Physics 2009-10-30 S. Markoff , F. Melia , I. Sarcevic

Disk galaxies are in hydrostatic equilibrium along their vertical axis. The pressure allowing for this configuration consists of thermal, turbulent, magnetic and cosmic ray components. For the Milky Way(MW) the thermal pressure contributes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Yuval Birnboim

Observed accretion rates onto the Milky-Way and other local spirals fall short of that required to sustain star formation for cosmological timescales. A potential avenue for this unseen accretion is an inflow in the volume-filling hot phase…

A supermassive black hole (SMBH) of $\sim 3\times 10^6 \, \rm M_\odot$ was recently detected via dynamical measurements at the center of the dwarf galaxy Leo I. Standing $\sim 2$ orders of magnitude above standard scaling relations, this…

Astrophysics of Galaxies · Physics 2022-11-29 Fabio Pacucci , Abraham Loeb

The evidence for the presence of a concentration of dark matter at the Galactic center is now very compelling. There is no question that the stellar and gas kinematics within 0.01 pc is dominated by under-luminous matter in the form of…

Astrophysics · Physics 2009-10-30 Fulvio Melia , Robert Coker

The effect of AGN wind feedback on the accretion rate and mass evolution of supermassive black holes (SMBH) is considered. It is shown, under reasonable assumptions, that the rate at which gas can be supplied to a SMBH at the center of a…

Astrophysics of Galaxies · Physics 2017-11-29 Amir Levinson , Ehud Nakar

Observations of the black hole in the center of the Milky Way with the Event Horizon Telescope at 1.3 mm have revealed a size of the emitting region that is smaller than the size of the black-hole shadow. This can be reconciled with the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Dimitrios Psaltis , Ramesh Narayan , Vincent L. Fish , Avery E. Broderick , Abraham Loeb , Sheperd S. Doeleman

Numerical simulations of black hole hot accretion flows have shown the existence of strong wind. Those works focus only on the region close to black hole thus it is unknown whether or where the wind production stops at large radii. To…

High Energy Astrophysical Phenomena · Physics 2016-06-01 De-Fu Bu , Feng Yuan , Zhao-Ming Gan , Xiao-Hong Yang

In recent years, near-IR and X-ray flares have been detected from the Galaxy's central radio point source, Sagittarius A* (Sgr A*), believed to be a \~3.10^6 solar masses supermassive black hole. In some cases, the transient emission…

Astrophysics · Physics 2009-11-13 Michel Tagger , Fulvio Melia

The Galactic center provides a unique laboratory to study the interaction of a supermassive black hole (SMBH) with its gaseous and stellar environment. Simulations to determine the accretion of stellar winds from the surrounding O-stars…

Astrophysics of Galaxies · Physics 2016-01-20 Nora Lützgendorf , Edwin van der Helm , Inti Pelupessy , Simon Portegies Zwart

We consider a model in which Sgr A*, the 3.5x10^6 M_sun supermassive black hole candidate at the Galactic Center, is a compact object with a surface. Given the very low quiescent luminosity of Sgr A* in the near infrared, the existence of a…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Ramesh Narayan

Winds from massive stars supply ~ 10^{-3} solar masss/year of gas to the central parsec of the Galactic Center. Spherically symmetric hydrodynamic calculations show that ~ 1 % of this gas, or ~ 10^{-5} solar masses/year, flows in towards…

Astrophysics · Physics 2009-11-10 Eliot Quataert

Recent measurements, of the velocities of stars near the center of the Milky Way have provided the strongest evidence for the presence of a supermassive black hole in a galaxy, but the observational uncertainties poorly constrain many of…

Astrophysics · Physics 2009-10-31 A. Ghez , M. Morris , E. E. Becklin , T. Kremenek , A. Tanner

The central supermassive black hole (SMBH) of the Andromeda galaxy, known as M31*, exhibits dim electromagnetic emission and is inferred to have an extremely low accretion rate for its remarkable mass ($\sim10^8~\rm~M_\odot$). In this work,…

Astrophysics of Galaxies · Physics 2025-07-16 Zhao Su , Zhiyuan Li , Zongnan Li

The recent detection of polarized radiation from Sgr A* requires a non-thermal electron distribution for the emitting plasma. The Faraday rotation measure must be small, placing strong limits on the density and magnetic field strength. We…

Astrophysics · Physics 2009-10-31 Eric Agol