{'fraction_non_alphanumeric': 0.01818181818181818, 'fraction_numerical': 0.0, 'mean_word_length': 4.777777777777778, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Removing Post-SAA Persistence in NICMOS Data

A general concern with NICMOS images is the issue of ‘persistence’, or residual charge from bright sources and cosmic rays that remains trapped in pixels and is gradually released during subsequent exposures. This is particularly noticeable after HST transits of the South Atlantic Anomaly (SAA), where the cosmic ray rate is so high that their residual flux contributes a significant noise component to many subsequent exposures. We describe the ‘SAAclean’ task which can be run on post-SAA NICMOS images to identify the amount of charge in each pixel that can be attributed to persistent flux from SAA cosmic rays, and apply a correction based on an SAA persistence model to remove this flux from the data. This task has so far been tested on a variety of NICMOS data, and this represents the most recent update of this task in the PyRAF/STSDAS environment to the HST observer community.