Cosmic ray propagation in interstellar and interplanetary media

Ming Zhang

Department of Physics and Space Sciences

Florida Institute of Technology, Melbourne, Florida, 32901, USA

 
The large bulk of cosmic rays up to the knee energy are produced in the Galaxy, mostly like by supernova remnants. Once they are released, they spend tens million years propagating through interstellar space filled gases before they dissipate from the Galaxy. Interaction between cosmic rays and interstellar medium can change the composition and spectrum of cosmic rays. A small fraction of cosmic rays pass through expanding solar wind with embedded magnetic fields and eventually reach the Earth deep in the heliosphere. The spectrum of cosmic ray observed at the Earth is modulated by the solar activity. In this talk, I show how cosmic ray spectrum, composition, and directional variation (anisotropy) are affect by cosmic ray transport in interstellar and heliospheric magnetic fields including turbulence.