Studying Young and Middle-aged Galactic Supernova Remnants in Gamma and X-rays
Abstract: Gamma rays are important carriers of information, as they are produced abundantly in galactic and extragalactic sources and propagate in space without being deflected by interstellar and intergalactic magnetic fields. They can be detected effectively with space-‐borne instruments like NASA's Fermi Gamma-‐ray Space Telescope (Fermi-LAT) and ground-based instruments, like the imaging atmospheric Cherenkov telescopes (IACTs), such as VERITAS, HESS, and MAGIC.
Some of the most intensively studied objects in the sky by Fermi-LAT and the IACTs are the Galactic supernova remnants (SNRs). Galactic SNR shocks provide good examples of high Mach number collisionless shocks, which are still not well understood. The SNR shocks are also the potential locations where part of the explosion energy is converted to cosmic ray energy. The SNR observations in radio, X-rays, and gamma rays caused by the acceleration of electrons and ions, are the radiative signatures of the relativistic particles present in SNRs.
In this talk I am going to focus on two Galactic SNRs detected by Fermi-LAT and X-ray satellites, 3C 391, a middle-‐aged mixed-‐morphology SNR interacting with molecular clouds, and Cas A, a young shell-like SNR, to show how multiwavelength data is used to understand the very high-energy emission mechanisms in SNRs.