"The Basic for Cosmic Ray Feedback in the Evolution of Galaxies and Beyond" by Ellen Zweibel, U. Wisconsin - Madison

Thursday, March 16, 2017 - 4:00pm to 5:00pm
Physics and Astronomy Colloquium

Thursdays, 4:00-5:00 pm

1-434 Physics and Astronomy (map)
Reception from 3:30-4:00 p.m.
(unless otherwise posted)

Guest Speaker: Ellen Zweibel (University of Wisconsin-Madison)

Talk Title:  “The Basic for Cosmic Ray Feedback in the Evolution of Galaxies and Beyond"


Star formation and supermassive black hole growth in galaxies appear to be self limiting. The mechanisms for self regulation are known as feedback. Cosmic rays, the relativistic particle component in interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics (GCRH), which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed.

For more information, contact Jay Hauser

We thank the following people for their contributions to the wine fund for the post-colloquium reception:
Prof. Dolores Bozovic, Prof. Robijn Bruinsma, Prof. Wesley Campbell, Prof. Bob Cousins, Prof. Jay Hauser, Prof. Eric Hudson, Robert Huff, Prof. HongWen Jiang, Prof. Alex Kusenko, Prof. John Miao, Prof. George Morales, Prof. Christoph Niemann, Prof. Rene Ong, Prof. James Rosenzweig, Prof. David Saltzberg, and Prof. Jean Turner

1-434 PAB