From Radio to Gamma-Rays: Interpreting the Multiwavelength Emission from Young Supernovae as a Probe of their Evolution, Progenitors, and Cosmic-Ray Acceleration

University Of Chicago, Chicago IL

Investigators

Abstract

When a massive star explodes as a supernova (SN), the shock wave from the explosion interacts with the material around the star, which has been ejected by the wind from the star during its lifetime. The rapidly moving shock wave heats this medium to high temperatures, and accelerates subatomic particles to high energies, thus producing radiation at all energies from low-energy radio waves to very high-energy gamma rays. A research group at the University of Chicago will study these interactions through computer simulations. They will interpret the signatures of the emitted radiation to infer the nature of the ambient medium with which the shocks interact, which can be related to the type of star that exploded. This will allow the investigators to relate the wide diversity of types of SNe to their different progenitor stars, helping to solve a very important problem in SNe and stellar astronomy. The researchers will also study the gamma rays emitted from young SNe. The project will provide research opportunities for undergraduate students, and one high school student each summer will be selected to work at the University of Chicago on supernova research. The lead scientists will also work with local school teachers to improve science education and give astronomy lectures to non-scientific audiences. Using sophisticated emission routines, including non-equilibrium ionization X-ray calculations, a radio synchrotron emission code, optical light curve fitting using the computer programs MESA and STELLA, and other available routines, the team will compute the X-ray, radio and optical emission arising from the interaction of the SN shock with the ambient medium. The programs will be used to fine-tune the models of the circumstellar medium structure, which in turn can be used to estimate the mass-loss properties of the progenitor, constrain ejecta parameters, and determine explosion parameters. Coupling to descriptions of mass-loss mechanisms will allow the investigators to probe the properties of the progenitor star. The detailed kinematic information from their models will be used to understand the acceleration of particles to relativistic energies in SN shocks, and predict the gamma-ray emission, which can be directly compared with data from ground and space-based telescopes. This project advances the goals of the NSF Windows on the Universe Big Idea. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.