Temperature dependent calibration products of the SWIFT x-ray telescope

The X-Ray Telescope (XRT) on board the Swift satellite is a sensitive imaging spectrometer utilizing a MAT-22 CCD at the Focal plane. The system was designed to operate the CCD at -100 °C +/- 1 °C for the duration of the mission. Due to a failure of the temperature control sub-system, the CCD operates under variable thermal conditions dictated by the view factor of the radiator- heatpipe sub-system to the Earth and sun. A temperature variation of up to 5° C is seen during a single orbit due to the satellite transition from sun light into eclipse and the full operational regime of the instrument ranges from temperatures of -75°C to -45°C due to the persistent heating/cooling effects of satellite orientation to the sun and earth. To maintain the highest quality data products possible from the XRT data stream, a recalibration of the XRT is required to account for this variable thermal environment. We present the methodology for and results from a temperature dependent analysis of on-orbit XRT data, collected during the Swift commissioning phase, used to produce gain, bias and warm pixel calibration products. We also discuss the quality of XRT science products capable with these temperature dependent calibration files and future plans for updates to these calibration products.