| Name: | Siddhartha Gupta |
| Affiliation: | Princeton University |
| Conference ID : | ASI2024_566 |
| Title : | From Thermal to Nonthermal: Understanding Electron Acceleration at Nonrelativistic Shocks Using First-principles Simulations |
| Authors : | Siddhartha Gupta(1,2), Damiano Caprioli(2,3) and Anatoly Spitkovsky(1) |
| Authors Affiliation: | 1. Department of Astrophysical Sciences, Princeton University, 4 Ivy Ln., Princeton, NJ 08544, USA
2. Department of Astronomy and Astrophysics, The University of Chicago, IL 60637, USA
3. Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637, USA |
| Mode of Presentation: | Oral |
| Abstract Category : | High Energy Phenomena, Fundamental Physics and Astronomy |
| Abstract : | Energetic charged particles, commonly referred to as cosmic rays, are one of the main contributors to the nonthermal energies in the universe. Although diffusive shock acceleration (DSA) is the promising mechanism for particle acceleration at shocks, the processes that promote electrons to DSA remain unclear. To solve this problem, we have performed first-principles kinetic particle-in-cell simulations of collisionless shocks, exploring a wide range of shock speeds, Alfvénic, and sonic Mach numbers. In this talk, I will discuss under which conditions electrons participate in the DSA at nonrelativistic collisionless shocks. I will also emphasize the critical role played by self-generated plasma instabilities resulting from the back-reaction of energetic particles in enhancing the energy of nonthermal particles. The results are key to understanding the nonthermal phenomenology of a variety of heliophysical/astrophysical sources that shine in radio, X-rays, and gamma-rays. |
