SPACE AND COSMIC RAY PHYSICS SEMINAR

University of Maryland
Atlantic Building, Room 2400
4:30 PM Monday, April 13, 2009
Coffee, Tea & Snacks 4:15-4:30 PM

Prof. Anatoly Spitkovsky
Princeton University

Particle Acceleration in Astrophysical Shocks

Nonthermal emission from a variety of astrophysical sources, including relativistic jets and supernova remnants, is often attributed to collisionless shocks. In this talk, I will present a summary of recent progress in modeling of collisionless shocks using first-principles plasma simulations. I will discuss the internal structure of relativistic and non-relativistic shocks, concentrating on the conditions necessary for particle acceleration. I will present simulations which show ab-initio Fermi acceleration of particles from the thermal pool to power-law distributions and set constraints on the shock acceleration efficiency and geometry. Other results that will be discussed include the amplification of magnetic fields by accelerated particles through streaming instabilities, and the electron-ion temperature equilibration in shocks. I will conclude with the applications of shock simulations to the physics of gamma-ray bursts, pulsar wind nebulae, and supernova remnants.