Date: Wednesday 12-Oct-2022
Time: 11:30-12:30 pm
Location: PSC 1136
Speaker: Rostom Mbarek (UMD)
Title: "Title: Particle Acceleration in Active Galactic Nuclei: From the Large Structures of Jets to the Kinetic Scale of Plasma Turbulence"
The origin of Ultra-High-Energy Cosmic Rays (UHECRs) and the highest-energy astrophysical neutrinos remains as one of the most prominent unresolved questions in astrophysics. We can shed light on such phenomena employing a thorough bottom-up approach to understand the spectra of UHECRs, neutrinos, and eventually x/gamma-rays from Active Galactic Nucleus (AGN) jets. In this respect, I will initially discuss an original theory of particle acceleration in AGN jets, i.e., the espresso mechanism, that we back by propagating protons and heavier elements in relativistic 3D MHD simulations of AGN jets accounting self-consistently for i) particle injection, ii) particle acceleration, iii) spectra of UHECRs, iv) effects of losses on UHECRs, and v) the resulting neutrino spectral features. Moving from the global scale of jets to the kinetic scales of the plasma, I will also present the first steps in understanding asymmetric reconnection in the relativistic regime both analytically and using Particle-in-Cell (PIC) simulations. Considering the turbulent nature of AGNs, asymmetric reconnection can potentially be the main driver of nonthermal lepton acceleration, and thus nonthermal radiation, important to modeling UHECR losses and neutrino production. If we have time, I will touch upon the interplay of these two regimes and potential ways of combining them.
Guidelines and format for the CTC Lunch seminars.
Past CTC Lunch seminars.
For other questions, contact the CTC Lunch host: Shmuel Bialy
SPECIAL ACCOMMODATIONS:
Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
