| Abstract: |
Despite its scientific importance, observations in the MeV gamma-ray band are still to be matured. Especially, MeV line gamma-ray observations are crucial to understanding cosmic matter production, e.g., 511 keV lines from positron annihilation and nuclear lines originating from nucleosynthesis. In 2021, NASA selected the Compton Spectrometer and Imager (COSI) as their next SMEX satellite mission. COSI can improve the line gamma-ray sensibility by one order of magnitude, and we will be in a new era of MeV gamma-ray observation in a few years. In this seminar, I will review the line gamma-ray observations by referring to previous and ongoing missions and discuss the current limitations of our scientific understanding. I also want to present the data analysis framework for the COSI project and our challenges towards the upcoming MeV observations. |
