Detector System for Time-Domain Astrophysics in the Soft Gamma-ray Regime

The Background and Transient Observer (BTO) is a student-led project to be flown on the upcoming Compton Spectrometer and Imager (COSI) Small Explorer mission. BTO will utilize a set of four scintillator detectors with SiPM readout to detect gamma-rays from >50% of the sky and from the Earth in the 20 keV—1 MeV range. These detectors will enhance the COSI mission by observing gamma-ray bursts, magnetars, and terrestrial gamma-ray flashes at lower (<100 keV) energies with spectral information over the whole range. Additionally, BTO will be used to improve models of COSI’s background. As a student run collaboration, BTO provides a unique opportunity for both graduate and undergraduate students to work alongside university researchers and engineers and gain confidence as future STEM leaders. This presentation will outline the design and future science goals of BTO.