Optical and Radio Variability of the Blazar S4 0954+658

IF 1.3 4区物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Astrophysical Bulletin Pub Date : 2024-03-02 DOI:10.1134/s1990341323600229

V. V. Vlasyuk, Yu. V. Sotnikova, A. E. Volvach, O. I. Spiridonova, V. A. Stolyarov, A. G. Mikhailov, Yu. A. Kovalev, Y. Y. Kovalev, M. L. Khabibullina, M. A. Kharinov, L. Yang, M. G. Mingaliev, T. A. Semenova, P. G. Zhekanis, T. V. Mufakharov, R. Yu. Udovitskiy, A. A. Kudryashova, L. N. Volvach, A. K. Erkenov, A. S. Moskvitin, E. V. Emelianov, T. A. Fatkhullin, P. G. Tsybulev, N. A. Nizhelsky, G. V. Zhekanis, E. V. Kravchenko

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引用次数: 0

Abstract

We present an optical-to-radio study of the BL Lac object S4 0954+658 observations during 1998–2023. The measurements were obtained with the SAO RAS Zeiss-1000 and AS-500/2 0.5-m telescopes in 2003–2023, with the RATAN-600 radio telescope at 1.25 (0.96, 1.1), 2.3, 4.7 (3.7, 3.9), 8.2 (7.7), 11.2, 22.3 (21.7) GHz in 1998–2023, with the IAA RAS RT-32 Zelenchukskaya and Badary telescopes at 5.05 and 8.63 GHz in 2020–2023, and with the RT-22 single-dish telescope of CrAO RAS at 36.8 GHz in 2009–2023. In this period the blazar was showing extremely high broadband activity with the variability amplitude of the flux densities up to 70–100\(\%\) both in the optical and radio domains. During the period of 2014–2023 the blazar displayed extremely high activity in the radio wavelengths, and we detected multiple radio flares of varying amplitude and duration. The large flares last on average from 0.3 to 1 year at 22–36.8 GHz and slightly longer at 5–11.2 GHz. The optical flares are shorter and last 7–50 days. The characteristic time scale \(\tau\) of variation at 5–22 GHz is about 100 days in the most active epoch of 2014–2023 and about 1000 days for the state with lower activity in 2009–2014. We found a general correlation between the optical, radio, and \(\gamma\)-ray flux variations, which suggesting that we observe the same photon population from different emission regions. We estimated the linear size of this region as 0.5–2 pc for different conditions. A broadband radio spectrum with two components of the S4 0954+658 jet was modeled using both electrons and protons as emitting particles. The results suggest that the synchrotron radio waves in this AGN may be produced by relativistic protons.

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耀星 S4 0954+658 的光学和射电变异性

摘要我们介绍了1998-2023年间对BL Lac天体S4 0954+658的光学-无线电研究观测结果。这些观测数据是在2003-2023年期间利用SAO RAS Zeiss-1000和AS-500/2 0.5米望远镜、RATAN-600射电望远镜在1.25 (0.96,1.1), 2.3, 4.7 (3.7, 3.9), 8.2 (7.7), 11.2, 22.在 1998-2023 年期间，将使用国际宇航科学院 RAS RT-32 Zelenchukskaya 和 Badaryt 望远镜，频率为 5.05 和 8.63 千兆赫；在 2009-2023 年期间，将使用克拉奥 RAS 的 RT-22 单碟望远镜，频率为 36.8 千兆赫。在此期间，该炽星在光学和射电领域都显示出极高的宽带活动性，通量密度的变异幅度高达70-100（\%\）。在2014-2023年期间，该星在射电波段显示出极高的活动性，我们探测到了多个不同振幅和持续时间的射电耀斑。大耀斑在22-36.8千兆赫波段平均持续0.3-1年，在5-11.2千兆赫波段持续时间稍长。在2014-2023年最活跃的纪元，5-22 GHz的特征变化时间尺度约为100天，而在2009-2014年较低活跃度的状态下约为1000天。我们发现光学、射电和（\gamma）-射线通量变化之间存在普遍的相关性，这表明我们观测到了来自不同发射区的相同光子群。在不同条件下，我们估计这个区域的线性大小为0.5-2 pc。使用双电子和质子作为发射粒子，模拟了 S4 0954+658 喷射的两个组成部分的宽带射电频谱。结果表明，该AGN中的同步射电波可能是由相对论质子产生的。

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来源期刊

Astrophysical Bulletin 地学天文-天文与天体物理

CiteScore

2.00

自引率

33.30%

发文量

审稿时长

>12 weeks

期刊介绍： Astrophysical Bulletin is an international peer reviewed journal that publishes the results of original research in various areas of modern astronomy and astrophysics, including observational and theoretical astrophysics, physics of the Sun, radio astronomy, stellar astronomy, extragalactic astronomy, cosmology, and astronomy methods and instrumentation.