Anindya Guria   (India)

 anguria @ mpia.de        anindya.guria @ mpi-hd.mpg.de

Particle acceleration in black hole jets

 

Relativistic jets from accreting black holes, in both active galactic nuclei and microquasars, are prime candidates for producing non-thermal particles and potentially contributing to the highest-energy cosmic rays. The core challenge lies in linking jet-scale dynamics and dissipation—modelled using GRMHD from the launching region to large distances—to the kinetic plasma physics responsible for particle acceleration.

I am interested in investigating which acceleration mechanisms are most efficient in jetted outflows and the conditions under which they operate. This includes Fermi-type processes at shocks and in shear layers, reconnection-driven acceleration in magnetised regions, and other collisionless kinetic pathways that emerge in turbulent plasmas. A key factor is the intense radiation environment near compact accretors: radiative losses, inverse-Compton drag, and pair loading can reshape particle spectra, amplify magnetic fields, and limit the maximum energy particles can attain.

On a global scale, I aim to understand how jet origin and composition influence these acceleration processes. For instance, differences between Blandford–Znajek and Blandford–Payne jets, as well as between pair-dominated and baryon-loaded outflows, may lead to variations in magnetisation, velocity structure, and dissipation sites. Combining kinetic approaches, such as relativistic PIC or Vlasov-type methods, with global GRMHD insights offers a pathway towards a unified understanding of particle acceleration in black hole jets and its associated high-energy signatures.

 

Supervisor:    Christian Fendt  (MPIA),  Brian Reville  (MPIK)