TY - JOUR
T1 - Collisionless Accretion onto Black Holes
T2 - Dynamics and Flares
AU - Galishnikova, Alisa
AU - Philippov, Alexander
AU - Quataert, Eliot
AU - Bacchini, Fabio
AU - Parfrey, Kyle
AU - Ripperda, Bart
N1 - Funding Information:
This work was supported by NASA Grant No. 80NSSC22K1054 and NSF Grant No. PHY-2231698. E. Q. and A. G. were supported in part by a Simons Investigator Grant from the Simons Foundation. Computing resources were provided and supported by Princeton Institute for Computational Science and Engineering; and by the VSC (Flemish Supercomputer Center), funded by the Research Foundation Flanders (FWO) and the Flemish Government—department EWI. This research is part of the Frontera computing project at the Texas Advanced Computing Center (LRAC-AST21006). Frontera is made possible by NSF Award OAC-1818253. F. B. acknowledges support from the FED-tWIN programme (profile Prf-2020-004, project “ENERGY”) issued by BELSPO. Support for this work was provided by NASA through the NASA Hubble Fellowship Grant No. HST-HF2-51518.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA Contract No. NAS5-26555. This research was facilitated by Multimessenger Plasma Physics Center (MPPC), NSF Grant No. PHY-2206607.
Publisher Copyright:
© 2023 American Physical Society.
PY - 2023/3/17
Y1 - 2023/3/17
N2 - We study the accretion of collisionless plasma onto a rotating black hole from first principles using axisymmetric general-relativistic particle-in-cell simulations. We carry out a side-by-side comparison of these results to analogous general-relativistic magnetohydrodynamic simulations. Although there are many similarities in the overall flow dynamics, three key differences between the kinetic and fluid simulations are identified. Magnetic reconnection is more efficient, and rapidly accelerates a nonthermal particle population, in our kinetic approach. In addition, the plasma in the kinetic simulations develops significant departures from thermal equilibrium, including pressure anisotropy that excites kinetic-scale instabilities, and a large field-aligned heat flux near the horizon that approaches the free-streaming value. We discuss the implications of our results for modeling event-horizon scale observations of Sgr A∗ and M87 by GRAVITY and the Event Horizon Telescope.
AB - We study the accretion of collisionless plasma onto a rotating black hole from first principles using axisymmetric general-relativistic particle-in-cell simulations. We carry out a side-by-side comparison of these results to analogous general-relativistic magnetohydrodynamic simulations. Although there are many similarities in the overall flow dynamics, three key differences between the kinetic and fluid simulations are identified. Magnetic reconnection is more efficient, and rapidly accelerates a nonthermal particle population, in our kinetic approach. In addition, the plasma in the kinetic simulations develops significant departures from thermal equilibrium, including pressure anisotropy that excites kinetic-scale instabilities, and a large field-aligned heat flux near the horizon that approaches the free-streaming value. We discuss the implications of our results for modeling event-horizon scale observations of Sgr A∗ and M87 by GRAVITY and the Event Horizon Telescope.
UR - http://www.scopus.com/inward/record.url?scp=85151265139&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85151265139&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.130.115201
DO - 10.1103/PhysRevLett.130.115201
M3 - Article
C2 - 37001105
AN - SCOPUS:85151265139
SN - 0031-9007
VL - 130
JO - Physical Review Letters
JF - Physical Review Letters
IS - 11
M1 - 115201
ER -