Nonthermal Emission of Tycho's Supernova Remnant

The time-dependent non-thermal particle and photon spectra are reproduced for a Type Ia SNR Tycho with radio, x-ray, GeV and TeV emission within the framework of the diffusive shock acceleration of the non-thermal particles. TeV photons can come from the inverse Compton scattering of relativistic electrons and from the π⁰−decay process in proton-proton interaction. The results show that (1) the hadronic case can model the observed multiwavelength spectrum well and, peculiarly, the π⁰-decay process appears to be necessary to explain the GeV emission; and (2) magnetic field amplification is vital in the SNR.