{'fraction_non_alphanumeric': 0.025380710659898477, 'fraction_numerical': 0.0676818950930626, 'mean_word_length': 4.381818181818182, '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}}
The Afterglow of Gamma-Ray Bursts: The Cases of GRB 970228 and GRB 970508

Highly radiative expansion of a relativistic shell is shown to explain all observed features of the afterglows of the two bursts GRB 970228 and GRB 970508. In particular, in the first case the observed time dependence ∝t-1.32 of the soft X-ray flux is easily reproduced. The same model, when the surrounding matter density scales as r-2, explains the afterglow of GRB 970508, which may at first sight appear at odds with that of GRB 970228. Quantitative agreement is also found with radio time delay and flux levels.