- Princeton Gravity Initiative
Organizers: Lev Arzamasskiy, Andrew Chael, Lia Medeiros, Elena Murchikova, Bart Ripperda, Elizabeth Tolman, George Wong, and Muni Zhou
Recent observations from the Event Horizon Telescope (EHT) collaboration provide resolved, quantitative measurements of synchrotron emission from the plasma around the nearby supermassive black holes at the centers of our galaxy and the nearby M87 galaxy. Combined with multiwavelength observational data from other scales, the event-horizon scale measurements from the EHT have been used to infer numerous constraints on the physical parameters of the accretion model and jet as well as on the properties of the central black holes themselves. Accretion in the systems targeted by the EHT is typically understood to comprise a radiatively inefficient flow, and the typical modeling and analysis procedure relies on a set of numerical fluid models, which make assumptions about collisionality, dissipation, and the distribution function of particles in the flow. In reality, the plasma is (near-)collisionless and most precisely represented by a kinetic description, which would make modeling the system on macroscopic scales prohibitively expensive. Kinetic plasma physics phenomena may drive the fluid out of equilibrium in ways that cannot be accounted for in the regular treatment of ideal magnetohydrodynamics, and there is growing observational evidence that these corrections may play a key role in producing accurate predictions that can be compared to observation. The goal of this workshop is to bring together researchers from the plasma physics, multiwavelength astronomy, and astrophysics communities in order to develop a realistic plan for improving the next generation of modeling and analysis efforts in interpreting the near-horizon emission from low-luminosity accreting supermassive black holes.