Princeton University Astroplasmas Seminar

The magnetospheres and jets of black holes host collisionless and highly magnetized plasmas. In such plasmas, relativistic magnetic reconnection may catalyze the release of free magnetic energy, powering quiescent and – especially – flaring emission. Exploring reconnection models in detail requires addressing multiwavelength observations that boast ever-increasing temporal and spatial resolution. This, in turn, demands a fully kinetic plasma description. Only then can one capture the collisionless coupling between position, momentum-space, and time that the observations probe. Thus, in my work, I use kinetic, particle-in-cell (PIC) simulations to model reconnection in regimes relevant to black hole magnetospheres and jets. I summarize results from two projects in this talk. The first project features PIC simulations of reconnection coupled to QED radiative physics. Here, the plasma particles radiate their energy in discrete quanta through Klein-Nishina inverse Compton scattering. Furthermore, the emitted gamma-ray photons can feed back on reconnection through electron-positron pair production. This radiative physics induces distinct observable signatures that can be compared to observations, both current and upcoming, of gamma-ray flares from flat-spectrum radio quasars. In the second part of my talk, I discuss ongoing efforts to model striped-jet launching from black holes using general relativistic PIC simulations. In this work, loops of alternating-polarity poloidal magnetic flux are accreted onto a spinning black hole. The rotational shear between the loop footpoints explosively tears the loops open via magnetic reconnection, potentially yielding observable magnetospheric counterpart emission to the formation of a large-scale striped jet.