Particle Acceleration in Astrophysical Plasmas
Coordinators: Don Ellison, Stefan Funk, Anatoly Spitkovsky
Scientific Advisors: Matthew G. Baring, Pasquale Blasi, Andrey Mikhailovich Bykov
Collisionless plasmas and shocks exist throughout the universe and, in a host of sources and diffuse regions, generally display strong evidence for efficient acceleration of superthermal particles. Recent theories and observations of young supernova remnants (SNRs), confirm that the efficient particle acceleration process in collisionless shocks can amplify existing turbulent magnetic fields by large factors. Thus, understanding the strongly coupled plasma physics of shocks, superthermal particles, and magnetic fields will have application in a wide variety of sources beyond SNRs including γ-ray bursts, active galactic nuclei, pulsar wind nebulae, and cosmic structure formation shocks in the outskirts of galaxy clusters. Our program will bring together theorists, plasma simulators, and observers to investigate the complex, nonlinear processes associated with particle acceleration in astrophysical plasmas with emphasis on the study of magnetic field amplification (MFA) in shocks undergoing efficient diffusive shock acceleration (DSA). We hope to foster longer-term collaborations on key areas such as:
- Investigation of fundamental questions concerning DSA coupled to MFA using semi-analytic techniques and particle-in-cell (PIC) simulations.
- Self-consistent spatial and energy dependent diffusion
- Resonant vs. non-resonant instabilities
- The effect of particle escape on MFA and the maximum particle energy a shock can produce
- Magnetic field generation and electron/proton injection and acceleration in PIC simulations
- Development of realistic models of cosmic ray (CR) production and subsequent broad-band radiation in SNRs to compare with recent and future observations.
- Leptonic or hadronic origin of GeV-TeV γ-ray emission from SNRs
- Integrated CR spectrum produced by SNRs of varying parameters
- Influence of CR production on thermal X-ray emission
- Determining the best way to capitalize on what promises to be an exceptionally active period for space- and ground-based observation with data coming on line from new and existing telescopes such as Chandra, XMM, Agile, HESS, Auger, Veritas, MAGIC, MILAGRO and GLAST.
There will be an associated conference to be held September 28 - October 2, 2009. As further information becomes available, an announcement and registration will be posted and listed under Upcoming Conferences, accessible from the KITP home page.