Solving the Galactic jigsaw: Probing high energy particle dynamics with multimessenger observations

Cosmic rays, high energy particles originating from outside of the solar system, are believed to be dominated by particles from our Galaxy at least up to the energy of 10^15 eV. Since the discovery of these particles in 1912, the origin, acceleration and propagation of these high energy particles have remained as century old questions. In the last few years, new results from space-borne experiments, such as the rise of the positron flux and hardening of the light nuclei, have begun to challenge our understanding of these particles. Complementing this, indirect observations of the cosmic rays via very high energy gamma rays have started to shed light on the various particle accelerators in our Universe. I will discuss what we expect to learn from near future experiments for both direct and indirect cosmic-ray measurements. For direct cosmic-ray measurements, I will focus on the balloon-borne experiment HELIX (high energy light isotope experiment), which will provide essential information to understand the propagation of Galactic cosmic rays. For indirect cosmic-ray measurements, I will show what we can learn from the future neutrino experiment IceCube Gen-2 and the future gamma-ray observatory CTA. Finally, I will highlight how these multimessenger observations come together to lead us toward a more coherent and complete picture of high energy particles in our Galaxy.

21 Feb 2018
Gore 104
Dr. Nahee Park, John Bahcall Fellow / Assistant Scientist Wisconsin IceCube Particle Astrophysics Center