Cosmic rays in the galactic environment

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This project is a theoretical and computational effort to understand quantitatively the effects of cosmic rays on the interstellar gas in galaxies. The Principal Investigator and a postdoctoral researcher supported and mentored under this award, along with collaborators, will develop and implement a cosmic-ray physics module for the widely used magnetohydrodynamic (MHD) code FLASH. This module will permit the simulation of anisotropic thermal conduction and viscosity, and a broad array of cosmic ray energy loss, acceleration, and transfer processes; the new module will be tested against the predictions of linear theory. The team will then use the enhanced FLASH code to (1) simulate the formation of, and internal physical conditions in, molecular clouds, using a two-fluid approximation; (2) simulate the effects of cosmic rays on important MHD instabilities known or suspected to be important in galactic disks; (3) model the correlation between radio and far-infrared emission observed in starburst galaxies; (4) model the radio synchrotron emission from galaxy halos; (5) model the diffuse gamma-ray emission from galactic winds; and (6) model the stripping of galactic gas through interactions with the surrounding intergalactic medium. The Principal Investigator will also participate in an extensive list of outreach activities, including creation of a museum exhibit, public lectures, design of planetarium shows, telescope tours, popular writings, and coordination between his academic department and schools.