The Properties of Reconnection Current Sheets in GRMHD Simulations of Radiatively Inefficient Accretion Flows
AffiliationUniv Arizona, Dept Astron
Univ Arizona, Steward Observ
Keywordsacceleration of particles
accretion, accretion disks
quasars: supermassive black holes
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationThe Properties of Reconnection Current Sheets in GRMHD Simulations of Radiatively Inefficient Accretion Flows 2018, 853 (2):184 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2018. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractNon-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 10(3), 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.
VersionFinal published version
SponsorsChandra Award [TM6-17006X]; NASA TCAN award [NNX14AB48G]; Radcliffe Institute for Advanced Study at Harvard University; John Simon Guggenheim Memorial Foundation; DoE [DE-SC0016542]; NASA Fermi [NNX-16AR75G]; NASA ATP [NNX-17AG21G]; NSF [ACI-1657507, AST-1716567]