Multi–wavelength flare observations of the blazar S5 1803+784

Nesci, R.; Cutini, S.; Stanghellini, C.; Martinelli, F.; Maselli, A.; Lipunov, V.M.; Kornilov, V.; Lopez, R.R.; Siviero, A.; Giroletti, M.; Orienti, M.

Авторы: Nesci R., Cutini S., Stanghellini C., Martinelli F., Maselli A., Lipunov V.M., Kornilov V., Lopez R.R., Siviero A., Giroletti M., Orienti M.
Журнал: Monthly Notices of the Royal Astronomical Society
Том: 502
Год издания: 2021
Издательство: Oxford Journals, Oxford University Press
Местоположение издательства: Oxford, UK, England
Первая страница: 6177
DOI: 10.1093/mnras/stab501
Аннотация: https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/stab501/6145519?redirectedFrom=fulltextAbstractThe radio, optical, and γ-ray light curves of the blazar S5 1803+784, from the beginning of the Fermi Large Area Telescope (LAT) mission in August 2008 until December 2018, are presented. The aim of this work is to look for correlations among different wavelengths useful for further theoretical studies. We analyzed all the data collected by Fermi LAT for this source, taking into account the presence of nearby sources, and we collected optical data from our own observations and public archive data to build the most complete optical and γ-ray light curve possible. Several γ-ray flares (F > 2.3 10−7ph(E > 0.1GeV) cm−2 s−1) with optical coverage were detected, all but one with corresponding optical enhancement; we also found two optical flares without a γ-ray counterpart. We obtained two Swift Target of Opportunity observations during the strong flare of 2015. Radio observations performed with VLBA and EVN through our proposals in the years 2016-2020 were analyzed to search for morphological changes after the major flares. The optical/γ-ray flux ratio at the flare peak varied for each flare. Very minor optical V-I colour changes were detected during the flares. The X-ray spectrum was well fitted by a power law with photon spectral index α=1.5, nearly independent of the flux level: no clear correlation with the optical or the γ-ray emission was found. The γ-ray spectral shape was well fitted by a power law with average photon index α= 2.2. These findings support an Inverse Compton origin for the high-energy emission of the source, nearly co-spatial with the optically emitting region. The radio maps showed two new components originating from the core and moving outwards, with ejection epochs compatible with the dates of the two largest γ-ray flares.
Добавил в систему: Тюрина Наталья Владимировна

	ИСТИНА	Войти в систему Регистрация
	ИСТИНА ЦЭМИ РАН
	Главная Поиск Статистика О проекте Помощь

ИСТИНА

ИСТИНА ЦЭМИ РАН

Multi–wavelength flare observations of the blazar S5 1803+784статья

Прикрепленные файлы