Stratospheric Terahertz Observatory 2 (STO2) Data Reduction

The Stratospheric Terahertz Observatory 2 (STO2) balloon observatory consists of a 0.8-meter Cassegrain telescope with single-pixel heterodyne receivers with hot-electron bolometer (HEB) mixers and a digital FFT 1-GHz bandwidth backend to observe [CII] at 1.9 THz (158 um) and [NII] at 1.46 THz (205 um). It flew from McMurdo station in the Antarctic in December 2016 allowing 20 days of observations of ~2.5sqdeg of the Galactic plane between 265deg < l < 335deg and -1deg < b < +1deg including Trumpler 14, parts of the Eta Carina region, NGC3576, and RCW38. The data reduction of these observations faced challenges comparable to the reduction of the Herschel/HIFI HEB bands 6 and 7. In this poster we describe the methods how we handled the removal of standing waves and other HEB receiver artifact that remained after the standard reference observation subtraction. We applied more than one reduction and calibration method to the data to confirm that the detected spectral features are fully preserved and properly calibrated. When the data reduction is finished, the final data products will become publicly available.