Modeling the Shell of Cassiopeia A to find the TeV Gamma-ray Emission Region

We will present the multi-wavelength modeling of the supernova remnant Cassiopeia A's shell based on radio, X-rays, and GeV-TeV gamma rays. Our aim is to estimate the location of TeV gamma rays with the help of spectral analysis of X-rays from different regions of the shell, because Chandra X-ray observations have a far better angular resolution than the gamma-ray measurements. Our analysis shows X-ray flux levels from various regions of the remnant to be different. We find that leptonic model is unable to explain the GeV and TeV data, simultaneously. So, we invoke a hadronic model as an additional component to explain the GeV and TeV data. Fig. 1: Multi-color (declination vs. right ascension in J2000) image of Cas A produced using Chandra X-ray data. The red, green, and blue color hues represent the energy ranges of (0.7,1.0), (1.0,3.5), and (3.5,8.0) keV, respectively. The red and green hues are smoothed in linear color scale, while the blue hues are shown in logarithmic scale to enhance the view of the smallest number of X- ray counts existing in the outer shell. The green ellipses represent the S, SW, SE, NW, and NE of the shell. The green, yellow, and white crosses and dashed lines correspond to the VERITAS, MAGIC, and Fermi-LAT detected gamma-ray emission locations and location error circles. The CCO location is shown with a red open diamond.