Particle acceleration in the M87 jet

The wealth of high quality data now available on the M87 jet inspired us to carry out a detailed analysis of the plasma physical conditions in the jet. In a companion paper (Lobanov, Hardee & Eilek, this proceedings) we identify a double-helix structure within the jet, and apply Kelvin-Helmholtz stability analysis to determine the physical state of the jet plasma. In this paper we treat the jet as a test case for in situ particle acceleration. We find that plasma turbulence is likely to exist at levels which can maintain the energy of electrons radiating in the radio to optical range, consistent with the broadband spectrum of the jet.Comment: 4 pages; to appear in New Astronomy Reviews, in proceedings of the meeting "The Physics of Relativistic Jets in the CHANDRA and XMM Era

Plasma physics in clusters of galaxies

Clusters of galaxies are the largest self-gravitating structures in the universe. Each cluster is filled with a large-scale plasma atmosphere, in which primordial matter is mixed with matter that has been processed inside stars. This is a wonderful plasma physics laboratory. Our diagnostics are the data we obtain from X-ray and radio telescopes. The thermal plasma is a strong X-ray source; from this we determine its density and temperature. Radio data reveal a relativistic component in the plasma, and first measurements of the intracluster magnetic field have now been made. Energization of the particles and the field must be related to the cosmological evolution of the cluster. The situation is made even richer by the few galaxies in each cluster which host radio jets. In these galaxies, electrodynamics near a massive black hole in the core of the galaxy lead to a collimated plasma beam which propagates from the nucleus out to supergalactic scales. These jets interact with the cluster plasma to form the structures known as radio galaxies. The interaction disturbs and energizes the cluster plasma. This complicates the story but also helps us understand both the radio jets and the cluster plasma.Comment: 12 pages, 6 figures, 3 in color. Invited review, to appear in Physics of Plasmas, May 2003. After publication it can be found at http://ojps.aip.org/po

Evolution of photon and particle spectra in compact, luminous objects

The physics of high energy photons and particles (especially electrons and positrons) in the compact, high-energy-density of galactic nuclei and quasars was investigated. A numerical code was developed which follows the nonlinear spectral evolution of a pair/photon plasma, due to two-body scattering and interaction process, in an unmagnetized system. The code was applied both to static plasmas and to relativistic expanding winds