{'fraction_non_alphanumeric': 0.037285607755406416, 'fraction_numerical': 0.035048471290082026, 'mean_word_length': 4.860262008733624, '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}}
High Temporal Resolution XMM-Newton Monitoring of PKS 2155–304

The bright, strongly variable BL Lacertae object PKS 2155-304 was observed by XMM-Newton for two essentially uninterrupted periods of ~11 and 16 hr on 2000 May 30-31. The strongest variations occurred in the highest energy bands. After scaling for this effect, the three softest bands (0.1-1.7 keV) showed strong correlation with no measurable lag to reliable limits of |τ| ≲ 0.3 hr. However, the hardest band (~3 keV) was less well correlated with the other three, especially on short timescales, showing deviations of ~10%-20% in ~1 hr, although, again, no significant interband lag was detected. This result and examination of previous ASCA and BeppoSAX cross-correlation functions suggest that previous claims of soft lags on timescales of 0.3-4 hr could well be an artifact of periodic interruptions due to Earth occultation every 1.6 hr. Previous determinations of the magnetic field/bulk Lorentz factor were therefore premature since these data provide only a lower limit of Bγ1/3 ≳ 2.5 G. The hardest band encompasses the spectral region above the high-energy break; its enhanced variability could be indicating that the break energy of the synchrotron spectrum, and therefore of the underlying electron energy distribution, changes independently of the lower energies.