10/7 張祥光 (Hsiang-Kuang Chang, NTHU Astronomy)
Gamma Ray Bursts (GRBs) and the Gamma-ray Transients Monitor (GTM) project
Gamma Ray Bursts (GRBs) were discovered more than half a century ago. Their nature remained highly mysterious since then until the detection of their multi-wavelength afterglows and host galaxies in late 90’s, which eventually allowed to measure the redshift of GRBs and to establish their cosmological distance scale. These advances were based on extensive efforts of GRB monitoring and follow-up observations. The Gamma-ray Transients Monitor (GTM), whose main goal is to monitor GBRs in the energy band from 50 keV to 2 MeV, is a secondary payload on board Formosat-8B (FS-8B), a Taiwanese remote-sensing satellite scheduled to launch in 2024. GTM consists of two identical modules located on two opposite sides of FS-8B. Each module has four sensor units facing different directions to cover half of the sky. The two modules will then cover the whole sky, including the direction occulted by the Earth. Each sensor unit is composed of a GAGG scintillator array (50 mm × 50 mm × 8 mm) to be readout by SiPM with 16 pixel-channels. GTM is expected to detect about 40 GRBs per year.