Speaker
Description
HESS J1804-216 is one of the brightest yet most mysterious TeV gamma-ray sources discovered so far. Previous arcminute-scale investigations of the interstellar medium (ISM) surrounding this source revealed that HESS J1804-216 is likely powered by a middle-aged supernova remnant (SNR) or pulsar. SNRs are believed to accelerate cosmic-ray protons at their shock front. These cosmic rays interact with the ISM and produce TeV gamma rays. In this investigation, the spatial and spectral distributions of cosmic rays are generated for a range of model parameters, describing, amongst others, the diffusion or the injection spectrum of cosmic rays. Based on these cosmic-ray distributions and measurements of the ISM, the spatial and spectral distributions of gamma rays are created. A comparison between these models and gamma-ray observations may reveal the origin and corresponding acceleration processes at play for HESS J1804-216. In this contribution, the modelled morphologies of two nearby potential cosmic-ray accelerators -- SNR G8.7-0.1 and the progenitor SNR of PSR J1803-2137 -- and their comparison to recent observations will be discussed. More detailed features in the morphology may be resolved with the next-generation Cherenkov Telescope Array, which will provide unprecedented angular resolution and sensitivity.
