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Related papers: Low angular momentum flow model of Sgr A* activity

200 papers

We present simulation results examining the presence and behavior of standing shocks in zero-energy low angular momentum advective accretion flows and explore their (in)stabilities properties taking into account various specific angular…

High Energy Astrophysical Phenomena · Physics 2024-12-18 Jun-Xiang Huang , Chandra B. Singh

The Galactic center provides a unique astrophysical laboratory for us to study various astrophysical processes. In this paper, we review and outline the latest results from observations of Sgr~A$^*$ in terms of source structure and…

Astrophysics · Physics 2007-05-23 Feng Yuan , Jun-Hui Zhao

We present numerical models of the gas dynamics in the inner parsec of the Galactic centre. We follow the gas from its origin as stellar winds of several observed young massive stars, until it is either captured by the central black hole,…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Jorge Cuadra , Sergei Nayakshin , Q. Daniel Wang

We examine the effects of magnetic field on low angular momentum flows with standing shock around black holes in two dimensions. The magnetic field brings change in behavior and location of the shock which results in regularly or…

High Energy Astrophysical Phenomena · Physics 2019-03-27 Toru Okuda , Chandra B. Singh , Santabrata Das , Ramiz Aktar , Anuj Nandi , Elisabete M. de Gouveia Dal Pino

The supermassive black hole in the center of our Galaxy, Sgr A*, is unique because the angular size of the black hole is the largest in the sky thus providing detailed boundary conditions on, and much less freedom for, accretion flow…

Astrophysics · Physics 2009-11-11 Feng Yuan

In accretion-based models for Sgr A* the X-ray, infrared, and millimeter emission arise in a hot, geometrically thick accretion flow close to the black hole. The spectrum and size of the source depend on the black hole mass accretion rate…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Monika Moscibrodzka , Hotaka Shiokawa , Charles F. Gammie , Joshua C. Dolence

We conduct a survey of numerical simulations to probe the structure and appearance of non-radiative black hole accretion flows like the supermassive black hole at the Galactic centre. We find a generic set of solutions, and make specific…

Astrophysics of Galaxies · Physics 2015-03-17 Bijia Pang , Ue-Li Pen , Christopher D. Matzner , Stephen R. Green , Matthias Liebendörfer

We run three long-timescale general-relativistic magnetohydrodynamic simulations of radiatively inefficient accretion flows onto non-rotating black holes. Our aim is to achieve steady-state behavior out to large radii and understand the…

High Energy Astrophysical Phenomena · Physics 2020-03-11 Christopher J. White , Eliot Quataert , Charles F. Gammie

Sgr A*, the supermassive black hole (SMBH) at the center of our Milky Way Galaxy, is known to be a variable source of X-ray, near-infrared (NIR), and submillimeter (submm) radiation and therefore a prime candidate to study the…

The radio source Sagittarius A* (Sgr A*) is believed to be a hot, inhomogeneous, magnetized plasma flowing near the event horizon of the 3 million solar mass black hole at the galactic center. At a distance of 8000 parsecs the black hole…

Astrophysics · Physics 2008-11-26 Scott C. Noble , Po Kin Leung , Charles F. Gammie , Laura G. Book

Upcoming Event Horizon Telescope (EHT) observations will provide a unique opportunity to reveal the innermost region of the radiative inefficient accretion flow (RIAF) around the Galactic black hole, Sgr A*. Depending on the flow dynamics…

High Energy Astrophysical Phenomena · Physics 2018-09-06 Hung-Yi Pu , Avery E. Broderick

Millimeter polarimetry of Sgr A* probes the linearly polarized emission region on a scale of $\sim 10$ Schwarzschild radii ($R_S$) as well as the dense, magnetized accretion flow on scales out to the Bondi radius ($\sim 10^5 R_S$) through…

We present three-dimensional numerical magnetohydrodynamic simulations of radiatively inefficient spherical accretion onto a black hole. The simulations are initialized with a Bondi flow, and with a weak, dynamically unimportant,…

Astrophysics · Physics 2009-11-06 Igor V. Igumenshchev , Ramesh Narayan

Images from the vicinity of the black hole horizon at the Galactic centre (Sgr A*) could be obtained in the near future with a Very Large Baseline Array of sub-millimetre telescopes. The recently observed short-term infrared and X-ray…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Abraham Loeb

We report on the first phase of our study of slightly rotating accretion flows onto black holes. We consider inviscid accretion flows with a spherically symmetric density distribution at the outer boundary, but with spherical symmetry…

Astrophysics · Physics 2009-11-07 D. Proga , M. C. Begelman

I review radiatively inefficient accretion flow models for the 2.6 million solar mass black hole (BH) in the Galactic Center. I argue for a 'concordance model' of Sgr A*: both theory and observations suggest that hot ambient gas around the…

Astrophysics · Physics 2009-11-07 Eliot Quataert

Context. The properties of the accretion flow surrounding the supermassive central black hole of the Galaxy, Sgr A*, will be scrutinized by the new-generation instrument GRAVITY and the Event Horizon Telescope (EHT). Developing fast,…

High Energy Astrophysical Phenomena · Physics 2019-04-17 F. H. Vincent , M. A. Abramowicz , A. A. Zdziarski , M. Wielgus , T. Paumard , G. Perrin , O. Straub

We present the relativistic 2D and 3D GRMHD simulation of axisymmetric, inviscid, hydrodynamic accretion flows in a fixed Kerr black hole gravitational field. The flow is having low angular momentum with respect to Keplerian one. A…

High Energy Astrophysical Phenomena · Physics 2020-02-28 Ishika Palit , Agnieszka Janiuk , Petra Sukova

In this proceeding, we provide a novel approach to study the General Relativistic Magnetohydrodynamic (GRMHD) accretion flows around rotating black holes (BHs). In doing so, we choose a sub-Keplerian distribution of angular momentum of the…

High Energy Astrophysical Phenomena · Physics 2025-03-11 Samik Mitra

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We have analyzed a comprehensive submillimeter (including new observations simultaneous with…