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Optical and Radio Variability of the Blazar S4 0954+658

Fuente: arXiv

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Main Authors:	Vlasyuk, V. V., Sotnikova, Yu. V., Volvach, A. E., Spiridonova, O. I., Stolyarov, V. A., Mikhailov, A. G., Kovalev, Yu. A., Kovalev, Y. Y., Khabibullina, M. L., Kharinov, M. A., Yang, L., Mingaliev, M. G., Semenova, T. A., Zhekanis, P. G., Mufakharov, T. V., Udovitskiy, R. Yu., Kudryashova, A. A., Volvach, L. N., Erkenov, A. K., Moskvitin, A. S., Emelianov, E. V., Fatkhullin, T. A., Tsybulev, P. G., Nizhelsky, N. A., Zhekanis, G. V., Kravchenko, E. V.
Format:	Preprint
Published:	2024
Subjects:	High Energy Astrophysical Phenomena
Online Access:	Acceder al recurso
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author	Vlasyuk, V. V. Sotnikova, Yu. V. Volvach, A. E. Spiridonova, O. I. Stolyarov, V. A. Mikhailov, A. G. Kovalev, Yu. A. Kovalev, Y. Y. Khabibullina, M. L. Kharinov, M. A. Yang, L. Mingaliev, M. G. Semenova, T. A. Zhekanis, P. G. Mufakharov, T. V. Udovitskiy, R. Yu. Kudryashova, A. A. Volvach, L. N. Erkenov, A. K. Moskvitin, A. S. Emelianov, E. V. Fatkhullin, T. A. Tsybulev, P. G. Nizhelsky, N. A. Zhekanis, G. V. Kravchenko, E. V.
author_facet	Vlasyuk, V. V. Sotnikova, Yu. V. Volvach, A. E. Spiridonova, O. I. Stolyarov, V. A. Mikhailov, A. G. Kovalev, Yu. A. Kovalev, Y. Y. Khabibullina, M. L. Kharinov, M. A. Yang, L. Mingaliev, M. G. Semenova, T. A. Zhekanis, P. G. Mufakharov, T. V. Udovitskiy, R. Yu. Kudryashova, A. A. Volvach, L. N. Erkenov, A. K. Moskvitin, A. S. Emelianov, E. V. Fatkhullin, T. A. Tsybulev, P. G. Nizhelsky, N. A. Zhekanis, G. V. Kravchenko, E. V.
contents	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 1-m 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 had been showing extremely high broadband activity with the variability amplitude of flux densities up to 70-100% both in the optical and radio domains. In the period of 2014-2023 the blazar had been showing the historically highest 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. In the most active epoch of 2018-2023 the characteristic time scale $τ$ of variation at 5-22 GHz is about 100 days and about 1000 days for the state with lower activity in 2009-2014. We found a general correlation between the optical, radio, and $γ$-ray flux variations, which suggests that we observe the same photon population from different emission regions. We estimated linear size of this region as 0.5-2 pc for different epochs. A broadband two components radio spectrum of S4 0954+658 jet was modelled by using both electrons and protons as emitting particles. It is shown that the synchrotron radio waves in this AGN may be generated by relativistic protons.
format	Preprint
id	arxiv_https___arxiv_org_abs_2401_03992
institution	arXiv
publishDate	2024
record_format	arxiv
spellingShingle	Optical and Radio Variability of the Blazar S4 0954+658 Vlasyuk, V. V. Sotnikova, Yu. V. Volvach, A. E. Spiridonova, O. I. Stolyarov, V. A. Mikhailov, A. G. Kovalev, Yu. A. Kovalev, Y. Y. Khabibullina, M. L. Kharinov, M. A. Yang, L. Mingaliev, M. G. Semenova, T. A. Zhekanis, P. G. Mufakharov, T. V. Udovitskiy, R. Yu. Kudryashova, A. A. Volvach, L. N. Erkenov, A. K. Moskvitin, A. S. Emelianov, E. V. Fatkhullin, T. A. Tsybulev, P. G. Nizhelsky, N. A. Zhekanis, G. V. Kravchenko, E. V. High Energy Astrophysical Phenomena 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 1-m 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 had been showing extremely high broadband activity with the variability amplitude of flux densities up to 70-100% both in the optical and radio domains. In the period of 2014-2023 the blazar had been showing the historically highest 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. In the most active epoch of 2018-2023 the characteristic time scale $τ$ of variation at 5-22 GHz is about 100 days and about 1000 days for the state with lower activity in 2009-2014. We found a general correlation between the optical, radio, and $γ$-ray flux variations, which suggests that we observe the same photon population from different emission regions. We estimated linear size of this region as 0.5-2 pc for different epochs. A broadband two components radio spectrum of S4 0954+658 jet was modelled by using both electrons and protons as emitting particles. It is shown that the synchrotron radio waves in this AGN may be generated by relativistic protons.
title	Optical and Radio Variability of the Blazar S4 0954+658
topic	High Energy Astrophysical Phenomena
url	https://arxiv.org/abs/2401.03992