The Advanced Compton Telescope mission

Abstract The Advanced Compton Telescope (ACT), the next major step in γ-ray astronomy, will probe the fires where chemical elements are formed by enabling high resolution spectroscopy of nuclear emission from supernova explosions. ACT requires two orders of magnitude improvement in sensitivity over current gamma- ray observatories to achieve this goal, and will operate primarily in survey mode – covering 80% of the sky on every orbit. ACT will also enable new classes of compact object and GRB observations, including all-sky monitoring for transients and rapid localizations, high resolution spectra, high sensitivity to positron annihilation emission and other line features, and novel sensitivity to polarization. ACT was chosen by NASA for a 1-year Vision Mission concept study, with the primary goals of identifying the key technologies and developing the detailed mission concept. We discuss the scientific goals and capabilities of ACT, and an overview of the science mission.