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Constraints on the extragalactic magnetic field strength from blazar spectra based on 145 months of Fermi-LAT observationsстатья Исследовательская статья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Podlesnyi E.I., Dzhatdoev T.A., Galkin V.I.
- Журнал: Monthly Notices of the Royal Astronomical Society
- Том: 516
- Номер: 4
- Год издания: 2022
- Издательство: Oxford Journals, Oxford University Press
- Местоположение издательства: Oxford, UK, England
- Первая страница: 5379
- Последняя страница: 5388
- DOI: 10.1093/mnras/stac2509
- Аннотация: Properties of the extragalactic magnetic field (EGMF) outside of clusters and filaments of the large-scale structure are essentially unknown. The EGMF could be probed with γ-ray observations of distant (redshift z > 0.1) blazars. TeV γ-rays from these sources are strongly absorbed on extragalactic background light photons; secondary electrons and positrons produce cascade γ-rays with the observable flux dependent on EGMF parameters. We put constraints on the EGMF strength using 145 months of Fermi-LAT observations of the blazars 1ES 1218+304, 1ES 1101−232, and 1ES 0347−121, and imaging atmospheric Cherenkov telescope observations of the same sources. We perform a series of full direct Monte Carlo simulations of intergalactic electromagnetic cascades with the ELMAG 3.01 code and construct a model of the observable spectra inside the point spread functions of the observing instruments for a range of EGMF strengths. We compare the observed spectra with the models for various values of the EGMF strength B and calculate the exclusion statistical significance for every value of B. We find that the values of the EGMF strength B ≤ 10^{−17} G are excluded at a high level of the statistical significance Z > 4σ for all the four options of the intrinsic spectral shape considered (power law, power law with exponential cutoff, log-parabola, and log-parabola with exponential cutoff). The value of B = 10^{−16} G is not excluded; it is still a viable option of the EGMF strength. These results were obtained for the case of steady sources.
- Добавил в систему: Подлесный Егор Игоревич
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