On-Ground Calibration Of The Halosat Science Instrument

HaloSat is a CubeSat-class microsatellite sensitive in the 0.4 to 7.0 keV energy band and designed to survey the entire sky in search of soft x-ray emissions from highly ionized oxygen residing in the halo of the Milky Way galaxy. Those observations will help constrain the mass and spatial distribution of the Milky Way halo and help us understand if hot galactic halos constitute a significant contribution to the overall cosmological baryon budget. We describe the science instrument calibration products, including channel-to-energy transformation, instrument energy resolution and instrument response, and the on-ground efforts that led to their creation. We also describe the alignment process used to obtain the field of view information for the HaloSat science instrument. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)