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BHI Colloquium

Monday, April 27, 2026
11:00 AM

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BHI Colloquium

Bart Ripperda

Description

Are We There Yet? First-principles Modeling of Multimessenger Signals in the Plasma Universe

Astrophysical black holes are surrounded by accretion disks, jets, magnetospheres, and coronae consisting of magnetized relativistic plasma. They produce observable multi wavelength and multi messenger signals from near the event horizon and it is currently unclear how this emission is exactly produced. The electromagnetic radiation typically has a non-thermal component, implying a power-law distribution of emitting relativistic electrons. Magnetic reconnection and plasma turbulence are viable mechanisms to tap the large reservoir of magnetic energy in these systems and accelerate electrons to extreme energies. The accelerated electrons can then emit high-energy photons that themselves may strongly interact with the plasma, rendering a highly nonlinear system. In some cases the electromagnetic emission is accompanied by a multi messenger signal in the form of neutrinos, cosmic rays, or gravitational waves. Modeling the emitting systems necessitates a combination of magnetohydrodynamic models to capture the global dynamics of the formation of dissipation regions, and a kinetic treatment of plasma processes that are responsible for particle acceleration, quantum electrodynamics effects like pair creation and annihilation, and radiation. I will present novel studies of accreting black holes and how they radiate in regions close to black hole event horizon, using both first-principles general relativistic kinetic particle-in-cell simulations and global large-scale three-dimensional magnetohydrodynamics models. With a combination of models, I determine where and how dissipation of magnetic energy occurs, what kind of emission signatures are typically produced, and what they can teach us about the nature of black holes.

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When

Monday, April 27, 2026 11:00 AM

Where

Inperson
BHI Conference Room and Zoom

BHI Publication

Expanding Sgr A* dynamical imaging capabilities with an African extension to the Event Horizon Telescope

April 1, 2023
Kantzas, D.; Markoff, S.; Lucchini, M.; Ceccobello, C.; Chatterjee, K.
Astrophysical jets are relativistic outflows that remain collimated for remarkably many orders of magnitude. Despite decades of research, the…
Read The BHI Publication