Martin Lemoine | Magnetized turbulent plasmas as high-energy accelerators

Friday 1 Nov 2024, 10:30 → 12:00 Europe/Berlin

1'202 Humboldt Adlershof campus, Gerthsen lecture hall 9.9., 13-15 (room 1'202)) (HU Adlershof campus, Institute of Physics)

How magnetized turbulent plasmas can accelerate charged particles to high energies represents a long-standing question with far-reaching implications for high-energy and multi-messenger astrophysics. It goes back to the seminal works of Enrico Fermi (1949, 1954) and nowadays, it is commonly invoked to model the generation of non-thermal particle spectra in a broad variety of astrophysical sites, including extreme, relativistic sources. This talk will introduce a theoretical picture to describe the physics at play, based on non-resonant interactions between particles and velocity structures. This model, which can be seen as a generalization of the original Fermi scenario, is supported by numerical simulations in the semi- to fully-relativistic regime. It also brings to light an interesting connection between the properties of intermittency of the turbulence and the spectrum of accelerated particles. I will then discuss some recent results regarding the evolution of the particle spectra on long timescales. Finally, I will discuss these findings in relation to neutrino production in magnetized, turbulent coronae of Seyfert galaxies.

Lemoine_DESY24.pdf