耀变体高活动期BL Lacertae的伽马射线与光学变异性的相关性
Correlation of gamma-ray and optical variability of BL~Lacertae during the period of high blazar activity
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中文总结 AI 辅助
通过研究BL Lacertae的伽马射线与光学变异性相关性，证实其伽马射线辐射源于同步自康普顿机制，发现12天时间延迟的相关峰值源于额外耀发，解释了孤儿耀发的起源。
中文摘要 AI 辅助
研究耀变体多波段流量变异性的相关性是限制其辐射机制和喷流物理参数的关键工具。我们研究了BL Lacertae在2022年9月（该源当时位于TESS视场内）约1天时间尺度上的伽马射线与光学变异性相关性，以及更长时间尺度（2022年4月至2023年9月，包含其伽马射线耀发，该耀发结束了高活动阶段的一系列耀发）的相关性。我们的分析证实同步自康普顿机制是伽马射线辐射的起源，其特征为零时间延迟。对于更长的时间间隔，离散相关函数（DCF）揭示了在约12天的时间延迟处存在第二个统计学显著峰值。我们证明该峰值源于某一波段中存在的额外耀发，该耀发伴随零时间延迟的伽马射线与光学耀发。我们将该孤儿耀发的起源解释为注入的高能电子团块在具有衰减磁场的喷流中传播，同时考虑电子的辐射冷却。
英文摘要
Investigating the correlation of flux variability in blazars across multiple spectral bands provides a key tool for constraining emission mechanisms and jet physical parameters. We study the gamma-ray and optical variability correlation of BL Lacertae on timescales of about 1 day during September 2022, when the source was within the TESS field of view, and over a longer period (April 2022 - September 2023) encompassing its gamma-ray flare, which finishes the series of flares during the high-activity phase. Our analysis confirms the Synchrotron Self-Compton mechanism as the origin of the gamma-ray emission, characterized by a zero time lag. For the longer interval, the Discrete Correlation Function (DCF) reveals a second statistically significant peak at the time lag of about 12 days. We demonstrate that this peak arises due to the presence of an additional flare in one of the bands, which accompanies a gamma-ray and optical flares correlated at zero time lag. We interpret the orphan flare origin in terms of the propagation of an injected blob of high-energy electrons along a jet with a decaying magnetic field, accounting for electron radiative cooling.
