标题： S5 0716+714耀变体在长时间低活动期的多波长变化分析 显示英文标题

标题： Multi-wavelength variability analysis of the blazar S5 0716+714 during a long-lasting period of low activity

摘要： 我们使用埃及和保加利亚的光学望远镜，对耀变体S5 0716+714进行了从2022年11月26日到2023年5月28日的多波长监测活动。 数据是在84个夜晚获取的，在其中的11个夜晚进行了夜间内监测。 我们还使用了光学和伽马射线调查数据。 在长期时间尺度上，我们发现自2020年初以来，S5 0716+714在光学和伽马射线中的活动逐渐减少。 在短期时间尺度上，各个光学光曲线之间具有很强的相关性，未观察到时间延迟。 V波段的百分比变化幅度等于97.59 +/- 0.02%。 我们发现中等程度的“越亮越平坦”的光谱行为，且“光谱指数-通量”反相关性强度随着波长的增加而减弱。 短期光曲线的主要特征是具有43.5 +/- 3.6天周期的瞬态准周期振荡。 V波段光曲线用两个螺旋运动的云团和一个同步辐射爆发进行建模。 我们估算了相应的参数，以及导致爆发区域的半径、磁场强度和电子洛伦兹因子的限制。 在夜间内时间尺度上，我们发现平滑的流量变化，没有爆发，并得出占空比在约10-20%范围内。 在夜间内时间尺度上缺乏爆发可能是由于暂时均匀的喷流流动，在防止开尔文-赫姆霍兹不稳定性方面没有形成湍流细胞。 数据分析显示，在观测期间，S5 0716+714在所有时间尺度上的活动都很低。 显示英文摘要

摘要： We conducted a multi-wavelength monitoring campaign of the blazar S5 0716+714 from 2022 November 26 to 2023 May 28 using optical telescopes in Egypt and Bulgaria. Data were taken during 84 nights in 11 of which intranight monitoring was performed. We also use optical and gamma-ray survey data. On long-term time-scales, we find a gradual decrease of the S5 0716+714 activity since the beginning of 2020 in both optical and gamma-rays. On short-term time-scales, the individual optical light curves are strongly correlated among each other with no time lags observed. The V-band percentage variability amplitude equals 97.59 +/- 0.02 per cent. We find moderate flatter-when-brighter spectral behaviour with the strength of the 'spectral index - flux' anti-correlation decreasing towards the longer wavelengths. The main feature of the short-term light curves is a transient quasi-periodic oscillation with a period of 43.5 +/- 3.6 d. The V-band light curve is modelled with two helically moving blobs and a synchrotron flare. We estimate the resulting parameters, as well as limits on the radius, magnetic field strength, and electron Lorentz factor of the region responsible for the flare. On intranight time-scales, we find smooth flux variations with no flares and derive a duty cycle in the range ~10-20 per cent. The lack of flares on intranight time-scales could result from a temporarily homogeneous jet flow without formation of turbulent cells in terms of prevented Kelvin-Helmholtz instability. The analysis of the data reveals a low activity of S5 0716+714 on all time-scales during the observation period.