arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2010.07136astro-ph.HE
收藏

blazar CTA 102在2016-2017年光学爆发期间光变曲线中的多波段准周期振荡

Multi-waveband quasi-periodic oscillations in the light curves of blazar CTA 102 during its 2016-2017 optical outburst

Arkadipta Sarkar, Pankaj Kushwaha, Alok C. Gupta, Varsha R. Chitnis, Paul J. Wiita

摘要:

耀变体光变曲线的准周期波动可以提供对潜在发射过程的深入了解。这种类型的通量调制暗示了导致发射的周期性物理过程。CTA 102是$z=1.032$的一个平谱射电类星体,自2016年以来一直表现出显着的活动。CTA 102的多波段光变曲线显示了2016-2017年耀斑期间准周期振荡的迹象。我们的目标是量化的存在下,任何周期性的发射通量在上述期间,并探讨的原因,可以引起it. Techniques,如Lomb-Scargle periodgram和加权小波z变换,观察在不同的频率发射的功率。为了量化主导周期的重要性,考虑功率谱的基本平滑弯曲幂律模型,采用蒙特卡罗技术。此外,使用自回归过程对光变曲线进行建模,以解析地获得主导周期的显著性。最后,使用广义自回归积分移动平均过程对光变曲线进行建模,以检查引入周期性分量是否导致统计上优选的模型。在2016-2017年耀斑期间,在blazar CTA 102的$γ$射线和光学通量中观察到了显著的同步准周期振荡(QPO)。周期性通量调制的主导周期为$\sim$ 7.6天,持续$\sim$ 8个周期(MJD 57710-57770)。所有使用的方法都指向$γ$射线和光通量中的显著($>4σ$)准周期调制。在探索周期性起源的同时,探索了几种可能的模型,并延伸到2016- 2017年的光学耀斑。对探测到的QPO的最好解释似乎是一个增强的发射区域,在喷流内部螺旋移动。

英文摘要:

Quasi-periodic fluctuations in the light curves of blazars can provide insight into the underlying emission process. This type of flux modulation hints at periodic physical processes that result in emission. CTA 102, a flat spectrum radio quasar at $z=1.032$, has displayed significant activity since 2016. The multi-waveband light curve of CTA 102 shows signs of quasi-periodic oscillations during the 2016-2017 flare. Our goal is to quantify the presence of any periodicity in the emitted flux during the mentioned period and to explore the causes that can give rise to it. Techniques such as the Lomb-Scargle periodogram and weighted wavelet z-transform were employed to observe the power emitted at different frequencies. To quantify the significance of the dominant period, Monte-Carlo techniques were employed considering an underlying smooth bending power-law model for the power spectrum. In addition, the light curve was modeled using an autoregressive process to analytically obtain the significance of the dominant period. Lastly, the light curve was modeled using a generalized autoregressive integrated moving average process to check whether introducing a periodic component results in a statistically preferable model. Significant, simultaneous quasi-periodic oscillations (QPOs) were observed in the $γ$-ray and optical fluxes of blazar CTA 102 during its 2016-2017 flare. The periodic flux modulation had a dominant period of $\sim$ 7.6 days and lasted for $\sim$ 8 cycles (MJD 57710-57770). All of the methods used point toward significant ($>4σ$) quasi-periodic modulation in both $γ$-ray and optical fluxes. Several possible models were explored while probing the origin of the periodicity, and by extension, the 2016--2017 optical flare. The best explanation for the detected QPO appears to be a region of enhanced emission, moving helically inside the jet.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑