Fading Hot Pixels in Hubble’s ACS/WFC Detector

Radiation damage to the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) detectors results in individual pixels with anomalously high dark currents, or hot pixels. These hot pixels have been growing in number since the installation of ACS on Hubble. Recent work has revealed that the rate of accumulation of dark current in many hot pixels is not constant over the course of an exposure, but decreases systematically as a function of exposure time. This behavior is consistent from exposure to exposure. This presents a problem for accurate removal of hot pixels from science images during dark correction. We present further analysis of these fading hot pixels over the lifetime of ACS as well as approaches to mitigating their effects.