So Long, Stratosphere: Imaging Galactic and Extragalactic Gamma-ray Sources with COSI

The Compton Spectrometer and Imager (COSI) is a wide-field-of-view Compton Gamma-ray telescope that operates in the 0.2 - 5 MeV bandpass. The predecessor of the Small Explorer mission was a balloon-borne instrument that had a successful 46-day flight in 2016. Using the data collected by the instrument during this flight and comparing these results with simulations, we present multiple examples of the imaging and spectral fitting capabilities of the balloon-borne version of this instrument. Compton telescopes have the advantage of a unique imaging response and provide the possibility of strong background suppression which is an important attribute for instruments that are background dominated. With its high-purity germanium strip detectors, COSI can precisely map gamma-ray line emission, image gamma-ray sources, and localize gamma-ray bursts. In this talk, we present the current imaging and spectral fitting techniques used for the 2016 balloon flight, and what we can expect for the upcoming Small Explorer space mission.