Validation of a CCD cosmic ray event simulator against Gaia in-orbit data

ESA’s astrometrymission Gaia was launched in 2013 to establish the most accurate and complete map of the Milky Wayby measuring the distance, position, proper motion, and astrophysical characteristics of two billion stars. It contains the largest focal plane ever flown in space comprising 106 CCDs. To downlink to Earth only useful data, an on-board algorithm was designed to discriminate between e.g. stars and cosmics- ionizing tracks left by energetic particles. A cosmic ray event generationsimulator was developed to train and optimize this on-board source detection algorithm. We can now validate this model against Gaia data.