Airborne detector for astrophysical gamma-ray measurements

A new method to measure high-energy gamma-rays from astronomical objects is presented. In this method we use commercial cargo airplanes to obtain an altitude near the shower maximum, i.e., ∼10 km above sea level. Gamma-rays with energies greater than 40 GeV can be detected by a lead-glass-based detector which has a surface area of 1.41 m2. The directions of the gamma-rays are determined by using the directions of the secondary electrons (and positrons) in the showers. The angular resolution obtained by this method is considered to be approximately 1°. The detector is sensitive to the gamma-ray point sources.