The Properties of Reconnection Current Sheets in GRMHD Simulations of Radiatively Inefficient Accretion Flows

David Ball, Feryal Özel, Dimitrios Psaltis, Chi Kwan Chan, Lorenzo Sironi

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

Non-ideal magnetohydrodynamic (MHD) effects may play a significant role in determining the dynamics, thermal properties, and observational signatures of radiatively inefficient accretion flows onto black holes. In particular, particle acceleration during magnetic reconnection events may influence black hole spectra and flaring properties. We use representative general relativistic magnetohydrodynamic (GRMHD) simulations of black hole accretion flows to identify and explore the structures and properties of current sheets as potential sites of magnetic reconnection. In the case of standard and normal evolution (SANE) disks, we find that in the reconnection sites, the plasma beta ranges from 0.1 to 1000, the magnetization ranges from 10-4 to 1, and the guide fields are weak compared with the reconnecting fields. In magnetically arrested (MAD) disks, we find typical values for plasma beta from 10-2 to 103, magnetizations from 10-3 to 10, and typically stronger guide fields, with strengths comparable to or greater than the reconnecting fields. These are critical parameters that govern the electron energy distribution resulting from magnetic reconnection and can be used in the context of plasma simulations to provide microphysics inputs to global simulations. We also find that ample magnetic energy is available in the reconnection regions to power the fluence of bright X-ray flares observed from the black hole in the center of the Milky Way.

Original languageEnglish (US)
Article number184
JournalAstrophysical Journal
Volume853
Issue number2
DOIs
StatePublished - Feb 1 2018

Keywords

  • acceleration of particles
  • accretion, accretion disks
  • magnetic reconnection
  • quasars: supermassive black holes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'The Properties of Reconnection Current Sheets in GRMHD Simulations of Radiatively Inefficient Accretion Flows'. Together they form a unique fingerprint.

  • Cite this