TOROS Image Reduction

Abstract

The Transient Optical Robotic Observatory of the South (TOROS) is a planned robotic observatory. The primary science goal of the observatory is to detect electromagnetic counterparts to gravitational wave phenomena. This project specifically focused on the characterization of the observatory’s Charged Coupled Device (CCD). Several sets of bias and dark images were taken by the TOROS camera in 2020 and 2022 to test the CCD’s dark current noise properties. These images were obtained and converted into .fits formatting using the CCD’s proprietary software, ARCHONGUI. Python was then used to median combine the bias images into a master bias image. Several master dark images were generated, using images taken at multiple exposure times. The master bias image was then subtracted from each master dark image to create a “subtraction” image at each exposure time. The mean and median pixel values for each of the subtraction files were then plotted at each exposure time to measure the dark current noise output of the camera and ensure the instrument was working properly. The results using the 2020 images showed that the camera noise initially appeared to be within the factory expectations (13-30 Analog Digital Units (ADU)/pixel at 300s exposures), but the results using the 2022 images suggest the camera may need some additional testing prior to its shipment to Cerro Macón in Argentina.