Space Sciences/Astrophysics Seminar with Lia Hankla on Kinetic and Two-Temperature Physics of Black Hole Accretion Disks and Coronae

Understanding the plasma physics of accretion disks and coronae around black holes is crucial for interpreting the radiation observed from these systems. However, these plasmas span several different physical regimes. They can be highly collisional and well-described by a single temperature, or collisionless with nonthermal particles that have been accelerated to high energies. In this talk, I will discuss several models for the plasmas in these regimes and implications for understanding black hole spin and evolution. I will explore the impact of two-temperature physics on the radial structure of accretion disks and consequences for emission from within the black hole's innermost stable circular orbit. Drawing an analogy to the solar wind, I will also suggest an alternative to the conventional paradigm of the X-ray corona in active galactic nuclei, using both large-scale general relativistic magnetohydrodynamic (GRMHD) simulations and small-scale particle-in-cell (PIC) simulations. Finally, I will discuss how observations can probe the dissipation processes in the corona and accretion disk.

Sponsored by the McDonnell Center for the Space Sciences.