The Journey of Cosmic Rays in our Galaxy

Cosmic rays are the most energetic particles in the Universe. They reach us at nearly the speed of light mostly from outside the Solar System. They encode the information on their origin and on the matter encountered in their journey to the Earth. Even though their discovery dates back to more than 100 years ago, cosmic-ray origin and transport are far from being understood.
Fortunately, during their journey in the Galaxy for several millions of years, cosmic rays leave their footprint behind. This allows us to learn about them and also about the Galaxy content. More precisely, after leaving their sources, cosmic ray propagate in the Galaxy and interact with the interstellar medium. As a result diffuse interstellar emission is produced that extends from radio to gamma rays. Observations of this diffuse interstellar emission, together with cosmic-ray measurements and comparison with models, is a powerful tool to learn about origin and propagation of cosmic rays, and on the Galaxy content.
I will address recent results and open questions on cosmic rays and on the associated diffuse interstellar emission. I will also discuss how to boost our understanding of cosmic rays and of the Galactic content, thanks to more and more precise cosmic-ray measurements, detailed multi-wavelength observations, and sophisticated modeling.

28 Feb 2018
Gore 104
Dr. Elena Orlando, Stanford University