论文标题
外层次背景光模型和GEV-TEV观察到Blazars
Extragalactic background light models and GeV-TeV observation of blazars
论文作者
论文摘要
在这项工作中，我们使用两种不同的方法来确定由于光子 - 光子相互作用而引起的E-E+产生引起的TEV伽马射线的不透明度。第一种方法，依赖模型的方法，使用各种EBL模型来估算TEV光子的红移和能量的不透明度。第二种方法是与模型无关的方法，依赖于使用Fermi-LAT和TEV带中的MEV-GEV能量范围内的Blazars同时观察到来自地面伽马射线望远镜的TEV频段。我们做出了一个下划线的假设，即在源源是源的固有TEV光谱的良好估计值或上限。我们将此方法应用于对不同红移的几个大麻的同时观察，以证明对六个突出的EBL模型的比较研究。独立于模型的方法预测的TEV光子的不透明性在系统上大于根据模型依赖性方法估计的光子。因此，可以使用对给定的红移对宇宙对TEV光子的不透明度设置严格的上限的伽马射线观测。
In this work, we use two different methods to determine the opacity of the TeV gamma-rays caused by the extragalactic background light (EBL) via e-e+ production due to photon-photon interaction. The first method, Model-Dependent Approach, uses various EBL models for estimating the opacity as a function of the redshift and energy of the TeV photons. The second method, Model-Independent Approach, relies on using the simultaneous observations of blazars in the MeV-GeV energy range from the Fermi-LAT and in the TeV band from the ground-based gamma-ray telescopes. We make the underline assumption that the extrapolation of the LAT spectrum of blazars to TeV energies is either a good estimate or an upper limit for the intrinsic TeV spectrum of a source. We apply this method on the simultaneous observations of a few blazars at different redshifts to demonstrate a comparative study of six prominent EBL models. Opacities of the TeV photons predicted by the model-independent approach are systematically larger than the ones estimated from the model-dependent method. Therefore, the gamma-ray observations of blazars can be used to set a strict upper limit on the opacity of the Universe to the TeV photons at a given redshift.
