Intraday multiband optical variability of BL Lacertae object S5 0716+714
Intraday multiband optical variability of BL Lacertae object S5 0716+714
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DOI：
10.1093/mnras/stab2164
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发表时间：
2021-08
影响因子：
4.8
通讯作者：
Yan Dai;Y. Fang;Xiaoyuan Zhang;Nankun Meng;Jianghua Wu;Zong-hong Zhu
中科院分区：
文献类型：
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作者：
Yan Dai;Y. Fang;Xiaoyuan Zhang;Nankun Meng;Jianghua Wu;Zong-hong Zhu
我们在2012年至2017年的11个夜晚用四台望远镜在四个光学波段监测了BL Lac天体S5 0716+714。该物体在大多数夜晚都很活跃。它在2012年11月7日最亮，I波段为11.720等，并在2016年1月22日达到最暗状态，R波段为15.770等，对应I波段为15.230等。所有谱带的日内变化均发生在第6天，而部分谱带的日内变化发生在第3天.在8个夜晚观察到强烈的蓝时亮色差。相关性分析显示，带间时间延迟4至40分钟，在5个晚上的日内变化。在该物体中观察到硬滞后和软滞后，表明射流中的复杂发射过程。对带间时间延迟的分析表明，辐射冷却可能偶尔主导S5 0716+714的光学时间延迟，但不能作为唯一的解释。
We monitored the BL Lac object S5 0716+714 in four optical wavebands with four telescopes on 11 nights from 2012 to 2017. The object was active during most of those nights. It was brightest on 2012 November 7 with 11.720 mag in the I band and reached the faintest state on 2016 January 22 with 15.770 mag in the R band corresponding to ∼15.230 mag in the I band. Intraday variations in all bands were found on 6 d, while in partial bands on 3 d. Strong bluer-when-brighter chromatism was observed on 8 nights. Correlation analyses revealed interband time delays from 4 to 40 min in the intraday variability on 5 nights. Both hard and soft lags were observed in this object, indicating complicated emission process in the jet. The analysis on the interband time delays indicated that the radiative cooling may dominate the optical time lags in S5 0716+714 occasionally, but cannot be invoked as the sole explanation.