683 citations · 955 across the 15 of their papers we have counts for
13 papers · 1 filter
Suppression of spiral density waves in collisionless accretion flows
Stephen Majeski, Matthew W. Kunz, Jason Dexter
Spiral density waves are ubiquitous phenomena in differentially rotating flows. They are non-modal, non-axisymmetric perturbations that, due to shear in the background flow, posses…
Electron-positron Pair Production in Global GRMHD Simulations of Black Hole Accretion Flows
Ho-Sang Chan, Jason Dexter, Mitchell C. Begelman
We present global, three-dimensional general relativistic magnetohydrodynamic simulations of accreting black holes that incorporate pair physics. Pairs are modeled as a passive sca…
Hot, Retrograde Tilted MADs: Misaligned, Precessing, and Shaped by Electromagnetic Torques
Sajal Gupta, Jason Dexter
Tilted accretion disks in the magnetically arrested (MAD) state may be present in X-ray binaries and active galactic nuclei such as Sgr A* and M87. We have carried out 3D global GR…
Demystifying flux eruptions: Magnetic flux transport in magnetically arrested disks
Jonatan Jacquemin-Ide, Mitchell C. Begelman, Beverly Lowell +3
Magnetically arrested disks (MADs) are a compelling model for explaining variability in low-luminosity active galactic nuclei (AGN), including horizon-scale outbursts like those ob…
The Impact of Plasma Angular Momentum on Magnetically Arrested Flows and Relativistic Jets in Hot Accretion Flows Around Black Holes
Ho-Sang Chan, Prasun Dhang, Jason Dexter +1
In certain scenarios, the accreted angular momentum of plasma onto a black hole could be low; however, how the accretion dynamics depend on the angular momentum content of the plas…
Polarimetric Signatures of Bulk Comptonization from within the Plunging Region of Accreting Black Holes
Ho-Sang Chan, Mitchell C. Begelman, Jason Dexter
Inverse Compton scattering by the thermal motions of electrons is believed to produce polarized hard X-rays in active galactic nuclei and black-hole binaries. Meanwhile, plasma wit…
Revealing the Accretion Flow in M87*: Insights from Faraday Rotation
Constanza Echiburú-Trujillo, Jason Dexter
The Faraday rotation measure (RM) is a commonly used tool to trace electron number density and magnetic fields in hot accretion flows, particularly in low-luminosity accreting supe…
The inner structure and thermodynamics of a thin accretion disc
A. Hankla, J. Dexter, N. Scepi
Using three-dimensional general relativistic magnetohydrodynamic simulations with electron and proton thermodynamics and an electron cooling function, we probe the inner radial and…
Energy Extraction from a Black Hole by a Strongly Magnetized Thin Accretion Disk
Prasun Dhang, Jason Dexter, Mitchell C. Begelman
The presence of a strong, large-scale magnetic field in an accretion flow leads to extraction of the rotational energy of the black hole (BH) through the Blandford-Znajek (BZ) proc…
Thermal solutions of strongly magnetized disks and the hysteresis in X-ray binaries
Nicolas Scepi, Jason Dexter, Mitchell C. Begelman +3
X-ray binaries (XRBs) exhibit spectral hysteresis for luminosities in the range , with a hard X-ray spectral state that persists from…
Shock-induced partial alignment in geometrically-thick tilted accretion disks around black holes
Sajal Gupta, Jason Dexter
We carry out idealized three-dimensional general-relativistic magnetohydrodynamic (GRMHD) simulations of prograde, weakly magnetized, and geometrically thick accretion flows where…
First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
The Event Horizon Telescope Collaboration
Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotr…
A Fast New Public Code for Computing Photon Orbits in a Kerr Spacetime
Jason Dexter, Eric Agol
Relativistic radiative transfer problems require the calculation of photon trajectories in curved spacetime. We present a novel technique for rapid and accurate calculation of null…