论文标题
基于145个月的Fermi-Lat观测值，对大黄体光谱的磁场强度的限制
Constraints on the extragalactic magnetic field strength from blazar spectra based on 145 months of Fermi-LAT observations
论文作者
论文摘要
簇外磁场（EGMF）的特性在集群和大规模结构的细丝外面是未知的。可以用$γ$ - 射线观察到遥远的（红移$ z> 0.1 $）的Blazars探测EGMF。来自这些来源的TEV $γ$射线被强烈吸收在外层状背景光光子上；二级电子和正电子产生级联$γ$射线，可观察到的通量取决于EGMF参数。我们使用145个月的Fermi-LAT观察结果对EGMF强度进行了约束，对Blazars 1ES 1ES 1218+304、1ES 1101-232和1ES 0347-121进行了限制，并成像大气Cherenkov望远镜观察相同来源的观测值。我们使用ELMAG 3.01代码进行了一系列完整的直接蒙特卡洛模拟，并对观测仪器内部的可观察到的光谱的模型构建了观察器仪器的点扩散功能，以构建一个可观察到的光谱模型。我们将观察到的光谱与模型的各种值进行比较，以$ b $ $ b $的各种值，并计算出$ b $的每个值的排除统计显着性。我们发现，EGMF强度的值$ b \ le 10^{ - 17} $ g被排除在统计显着性的高水平上$ z>4σ$，用于所考虑的内在频谱形状的所有四个选项（幂律，幂律，具有指数级别，log-parabola，log-parabola，log-parabola，log-parabola，log-parabola at tuepentuent cutoff cutoff uthereff useforfform的幂律）。 $ b = 10^{ - 16} $ g的值不排除；它仍然是EGMF强度的可行选择。对于稳定来源的情况，获得了这些结果。
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 $B \le 10^{-17}$ G are excluded at a high level of the statistical significance $Z > 4 σ$ for all the four options of the intrinsic spectral shape considered (power-law, power-law with exponential cutoff, log-parabola, 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.
