Astrophysics Colloquium: The Compton Spectrometer and Imager (COSI)

Abstract: The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) mission scheduled to launch in 2027. It features a wide field-of-view Compton telescope that will probe the under-explored MeV gamma-ray band (0.2-5 MeV) with unprecedented sensitivity, imaging the sky and performing precise spectroscopic measurements.

COSI’s primary science goals are: (1) uncover the origin of Galactic positrons; (2) reveal galactic element formation; (3) gain insight into extreme environments with polarization; and (4) probe the physics of multimessenger events.

In this colloquium, we will describe how COSI works, its capabilities, the challenges of analyzing Compton data, and how COSI will help advance our science goals.