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Related papers: The Accretion flow in M87 is really MAD

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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

In this study, we investigate the effect of resistivity on the dynamics of global magnetohydrodynamic accretion flows (Res-MHD) around a spinning supermassive black hole. We perform a comparative study of 2D and 3D resistive models around…

High Energy Astrophysical Phenomena · Physics 2025-07-10 Ramiz Aktar , Kuo-Chuan Pan , Toru Okuda

We present three-dimensional MHD simulations of rotating radiatively inefficient accretion flows onto black holes. In the simulations, we continuously inject magnetized matter into the computational domain near the outer boundary, and we…

Astrophysics · Physics 2009-11-07 Igor V. Igumenshchev , Ramesh Narayan , Marek A. Abramowicz

Supermassive black holes in galaxies spend majority of their lifetime in the low-luminosity regime, powered by hot accretion flow. Strong winds launched from the hot accretion flow have the potential to play an important role in active…

High Energy Astrophysical Phenomena · Physics 2024-03-04 Fangzheng Shi , Feng Yuan , Zhiyuan Li , Zhao Su , Suoqing Ji

A new general relativistic radiation magnetohydrodynamical code KORAL, is described, which employs the M1 scheme to close the radiation moment equations. The code has been successfully verified against a number of tests. Axisymmetric…

High Energy Astrophysical Phenomena · Physics 2014-03-05 A. Sadowski , R. Narayan , J. C. McKinney , A. Tchekhovskoy

It is widely accepted that quasars and other active galactic nuclei (AGN) are powered by accretion of matter onto a central supermassive black hole. While numerical simulations have demonstrated the importance of magnetic fields in…

High Energy Astrophysical Phenomena · Physics 2009-11-13 Peter B. Dobbie , Zdenka Kuncic , Geoffrey V. Bicknell , Raquel Salmeron

We have performed a series of two-dimensional two-temperature general relativistic magnetohydrodynamic simulations of magnetized accretion flows initiated from tori with different sizes and poloidal magnetic loop polarities. In these two…

High Energy Astrophysical Phenomena · Physics 2023-04-26 Hong-Xuan Jiang , Yosuke Mizuno , Christian M. Fromm , Antonios Nathanail

Magnetic fields regulate black hole (BH) accretion, governing both inflow and outflow dynamics. When a BH accumulates substantial vertical magnetic flux, it enters the magnetically arrested disk (MAD) state, where dynamically important…

High Energy Astrophysical Phenomena · Physics 2025-09-18 Koushik Chatterjee , Nicholas Kaaz , Matthew Liska , Alexander Tchekhovskoy , Sera Markoff

Chaotic cold accretion (CCA) profoundly differs from classic black hole accretion models. Using 3D high-resolution simulations, we probe the impact of rotation on the hot and cold accretion flow in a typical massive galaxy. In the hot mode,…

Astrophysics of Galaxies · Physics 2015-06-30 M. Gaspari , F. Brighenti , P. Temi

General relativistic magnetohydrodynamic (GRMHD) simulations of accreting black holes in the radiatively inefficient regime show that systems with sufficient magnetic poloidal flux become magnetically arrested disc (MAD) systems, with a…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Philip Mocz , Xinyi Guo

Three-dimensional numerical simulations of a hot accretion flow around a supermassive black hole are performed using the general relativity magneto-hydrodynamic (GRMHD) code Athena++. We focus on the case of SANE, with the initial magnetic…

High Energy Astrophysical Phenomena · Physics 2024-05-01 Miljenko Čemeljić , Feng Yuan , Hai Yang

Depending on the value of the accretion rate, black hole accretion is divided into cold and hot modes. The two modes have distinctly different physics and correspond to two feedback modes. Most previous feedback works either focus only on…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Doosoo Yoon , Feng Yuan , Jeremiah P. Ostriker , Luca Ciotti , Bocheng Zhu

This is the fourth paper of our series of works studying winds from hot accretion flows around black holes. In the first two papers, we have shown the existence of strong winds in hot accretion flows using hydrodynamical and…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Hai Yang , Feng Yuan , Ye-fei Yuan , Christopher J. White

We perform three-dimensional radiation-relativistic magnetohydrodynamic (3D Rad-RMHD) simulations of accretion flows around spinning active galactic nuclei (AGNs). Our study focuses on the magnetically arrested disk (MAD) state, adopting a…

High Energy Astrophysical Phenomena · Physics 2026-03-13 Ramiz Aktar , Kuo-Chuan Pan , Toru Okuda

Outflows and convective motions in accretion flows have been intensively discussed recently in the context of advection-dominated accretion flow (ADAF) based on two-dimensional (2D) and three-dimensional (3D) hydrodynamical simulations. We,…

Astrophysics · Physics 2007-05-23 Mami Machida , Ryoji Matsumoto , and Shin Mineshige

A supermassive black hole in the nucleus of an elliptical galaxy at the centre of a cool-core group or cluster of galaxies is immersed in hot gas. Bondi accretion should occur at a rate determined by the properties of the gas at the Bondi…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ramesh Narayan , Andrew C. Fabian

We present the detailed global structure of black hole accretion flows and outflows through newly performed two-dimensional radiation-magnetohydrodynamic simulations. By starting from a torus threaded with weak toroidal magnetic fields and…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Ken Ohsuga , Shin Mineshige

Chandra X-ray observations of the giant elliptical galaxy M87 resolve the thermal state of the hot interstellar medium into the accretion (Bondi) radius of its central 3 10^9 Msun black hole. We measure the X-ray gas temperature and density…

In this paper we use the imaging results of M87* from the EHT to calculate the rotational velocity of the inner edge of the accretion disk and find a value of $\sim$0.14c. We then calculate the dimensionless spin parameter, $a$, of the…

High Energy Astrophysical Phenomena · Physics 2025-05-26 Michael Drew , Joshua S. Stanway , Brett A. Patterson , Timothy J. Walton , Derek Ward-Thompson

Supermassive black holes at the centre of galactic nuclei mostly grow in mass through gas accretion over cosmic time. This process also modifies the angular momentum (or spin) of black holes, both in magnitude and in orientation. Despite…

Astrophysics of Galaxies · Physics 2018-04-25 Davide Fiacconi , Debora Sijacki , J. E. Pringle