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Related papers: Some First Steps Towards a Radiation GRMHD Code: R…

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We present a sub-grid model that emulates the magnetic dynamo operating in magnetized accretion disks. We have implemented this model in the general relativisic radiation magnetohydrodynamic (GRRMHD) code \koral, using results from local…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Aleksander Sadowski , Ramesh Narayan , Alexander Tchekhovskoy , David Abarca , Yucong Zhu , Jonathan C. McKinney

Simple assumptions made regarding electron thermodynamics often limit the extent to which general relativistic magnetohydrodynamic (GRMHD) simulations can be applied to observations of low-luminosity accreting black holes. We present,…

High Energy Astrophysical Phenomena · Physics 2015-10-15 Sean M. Ressler , Alexander Tchekhovskoy , Eliot Quataert , Mani Chandra , Charles F. Gammie

In this paper we present a major update to the general relativistic magnetohydrodynamics (GRMHD) code cuHARM, which adds fully covariant treatment of radiation transport and the subsequent radiation backreaction on the dynamics of the…

High Energy Astrophysical Phenomena · Physics 2025-08-22 John Wallace , Damien Bégué , Asaf Pe'er

General Relativistic (GR) Magnetohydrodynamic (MHD) simulations of black hole accretion find significant magnetic stresses near and inside the innermost stable circular orbit (ISCO), suggesting that such flows could radiate in a manner…

Astrophysics · Physics 2009-11-13 Kris Beckwith , John Hawley , Julian Krolik

We present two general relativistic radiation magnetohydrodynamics (GRRMHD) simulations of magnetically arrested disks (MADs) around non-spinning ($a_*=0$) and spinning ($a_*=0.9$) supermassive black holes (BHs). In each simulation, the…

High Energy Astrophysical Phenomena · Physics 2022-11-30 Brandon Curd , Ramesh Narayan

We investigate the accretion induced spin up of the black hole via numerical simulations. Our method is based on general-relativistic magneto-hydrodynamics of the slowly-rotating flows in the Kerr metric, where possibly transonic shock…

High Energy Astrophysical Phenomena · Physics 2021-05-26 Dominika Ł. Król , Agnieszka Janiuk

We study the general-relativistic dynamics of matter being accreted onto and ejected by a magnetised and nonrotating neutron star. The dynamics is followed in the framework of fully general relativistic magnetohydrodynamics (GRMHD) within…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Sercan Çıkıntoğlu , K. Yavuz Ekşi , Luciano Rezzolla

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

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

The influence of disc radiation capture upon black hole rotational evolution is negligible for radiatively inefficient discs. For the standard thin disc model it is a slight but potentially important effect leading to the equilibrium spin…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Pavel Abolmasov

We present the results of axisymmetric, time-dependent magnetohydrodynamic simulations of accretion flows around black holes. The calculations begin from a rotationally supported thick torus which contains a weak poloidal field. Accretion…

Astrophysics · Physics 2009-10-31 James M. Stone , James E. Pringle

Long-term observations have shown that black hole X-ray binaries exhibit strong, aperiodic variability on time-scales of a few milliseconds to seconds. The observed light curves display various characteristic features like a log-normal…

High Energy Astrophysical Phenomena · Physics 2020-07-28 D. A. Bollimpalli , R. Mahmoud , C. Done , P. C. Fragile , W. Kluźniak , R. Narayan , C. J. White

We investigate the long-term evolution of black hole accretion disks formed in neutron star mergers. These disks expel matter that contributes to an $r$-process kilonova, and can produce relativistic jets powering short gamma-ray bursts.…

High Energy Astrophysical Phenomena · Physics 2018-11-07 Rodrigo Fernández , Alexander Tchekhovskoy , Eliot Quataert , Francois Foucart , Daniel Kasen

Accreting supermassive black hole binaries are powerful multimessenger sources emitting both gravitational and EM radiation. Understanding the accretion dynamics of these systems and predicting their distinctive EM signals is crucial to…

We present the first spectral energy distributions produced self-consistently by 2.5D general relativistic magneto-hydrodynamical (GRMHD) numerical simulations, where radiative cooling is included in the dynamical calculation. As a case…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Samia Drappeau , Salomé Dibi , Jason Dexter , Sera Markoff , P. Chris Fragile

This paper presents a continuation of our efforts to numerically study accretion disks that are misaligned (tilted) with respect to the rotation axis of a Kerr black hole. Here we present results of a global numerical simulation which fully…

Astrophysics · Physics 2009-11-13 P. Chris Fragile , Omer M. Blaes , Peter Anninos , Jay D. Salmonson

The recent imaging of the M87 black hole at millimeter wavelengths by the Event Horizon Telescope (EHT) collaboration has triggered a renewed interest in numerical models for the accretion of magnetized plasma in the regime of general…

High Energy Astrophysical Phenomena · Physics 2020-01-08 N. Tomei , L. Del Zanna , M. Bugli , N. Bucciantini

Understanding the dynamics of low angular momentum accretion flow around black holes (BHs) is essential for probing extreme plasma behavior in strong gravity, where shock formation can naturally produce variability signatures. In this…

High Energy Astrophysical Phenomena · Physics 2025-08-27 Jirong Mao , Indu K. Dihingia , Yosuke Mizuno , Shigehiro Nagataki

To understand the decaying phase of outbursts in the black hole (BH) X-ray binaries (BH-XRBs), we performed very long general relativistic magneto-hydrodynamic (GRMHD) simulations of a geometrically thin accretion disk around a Kerr BH with…

High Energy Astrophysical Phenomena · Physics 2023-09-29 I. K. Dihingia , Y. Mizuno , P. Sharma

Context. The Bondi spherical accretion solution has been used to model accretion onto compact objects in a variety of situations, from interpretation of observations to subgrid models in cosmological simulations. Aims. We aim to investigate…

High Energy Astrophysical Phenomena · Physics 2025-09-03 Razieh Ranjbar , Héctor R. Olivares-Sánchez