Simulation studies of MACE gamma ray telescope : estimation of integral sensitivity, angular resolution and energy resolution

The MACE (Major Atmospheric Cherenkov Experiment) is an Imaging Atmospheric Cherenkov Telescope (IACT) located in Hanle, India. It has highest altitude of 4270 m among all the IACTs in the world. The high altitude of MACE along with its large reflector having diameter of 21 m is expected to yield wide energy coverage of 20 GeV to similar to 20 TeV. We have carried out detailed Monte Carlo simulations of the MACE response to gamma and cosmic ray showers in this energy range for various zenith angles between 0 degrees to 60 degrees. We estimated the variation of integral flux sensitivity, angular resolution and energy resolution as a function of energy, at various zenith angles. We find that the energy threshold of the MACE remains steady between similar to 30 GeV to similar to 50 GeV over the zenith angle range of 0 degrees to 40 degrees with integral flux sensitivity of similar to 2 % Crab. The Angular resolution of the MACE improves from 0.21 degrees near the energy threshold to 0.07 degrees at energy of > 1 TeV for zenith angle range of 0ffi to 40 degrees. The expected energy resolution of the MACE in the zenith angle range of 0ffi to 40 degrees varies from similar to 40 % near energy threshold to similar to 20 % for energies above 1 TeV. The MACE will detect Crab like point source within few minutes at all zenith angles, with best detection time of similar to 80 seconds occurring at zenith angle of 25 degrees.