PANGU: a sub-GeV gamma-ray detector proposed for the joint CAS-ESA misson call

The ESA Directorate of Science and Robotic Exploration (ESA-SRE) and the Chinese Academy of Sciences (CAS) have agreed to jointly pursue a scientific space mission, to be implemented by the ESA Science Programme and the Chinese National Space Science Centre (NSSC) under the CAS. In this talk, I will briefly describe a proposed space mission for the low energy gamma-ray observations. The highly successful Fermi mission has proved the great potential of studying astrophysics, cosmology and fundamental physics in high energy gamma rays. One area of improvement is in the 10 MeV to 1 GeV region, where the PSF of Fermi is limited by the presence of the Tungsten converters. Another area is the polarization measurement. It is also crucial to have a gamma-ray all sky survey mission running in parallel with HERD and CTA. PANGU (PAir-productioN Gamma-ray Unit) is a mission candidate proposed to the ESA-CAS joint mission. To achieve a PSF of ~1° at 100 MeV, PANGU proposes to use a fully active tracker use thin silicon strip detectors. Our proposal has been presented at the first dedicated workshop of the ESA-CAS joint mission, and was selected for oral presentation as the only high energy mission for the second workshop. PANUG mission involves ~100 scientists from both China and Europe.