论文标题
带有Tev bl lac物体的外乳外背景光的研究
Studies of Extragalactic Background Light with TeV BL Lac Objects
论文作者
论文摘要
非常高的能量（vhe; $ e \ geq $ 100GEV）$γ-$γ-$ ray rosmological距离被IR到紫外线带的外层次背景光（EBL）减弱。通过对比测得的与固有发射，可以得出EBL光子密度。但是，除了它们的综合效果外，固有光谱和EBL都不是分别已知的〜-〜。在这里，我们首先提出了一种柔性模型的光学深度方法，通过通过单区LACS对象的发射光谱通过单区Leptonic Synchrotron Self-Compton模型（SSC）拟合TEV BL LACS对象来研究EBL。我们几乎没有关于射流中电子能量分布（EED）的信息，这对于在SSC方案中构建光谱能量分布（SED）至关重要。基于当前的粒子加速模型，我们使用两种类型的EED i，e。，一个幂律对数 - parabola（PLLP）EED和损坏的幂律（BPL）EED来拟合观察到的光谱。我们获得EBL密度的上限约为30 N W M $^{ - 2} $ SR $^{ - 1} $，与已发布的测量相似。此外，我们提出了一种前所未有的方法来测试TEV对象中涉及的辐射机制，只需将降低的EBL密度与银河计数获得的极限进行比较，并证明至少对于某些BL LAC，应重新考虑单区SSC模型。
Very high energy (VHE; $E \geq$ 100GeV) $γ-$ray from cosmological distances are attenuated by the extragalactic background light (EBL) in the IR to UV band. By contrasting measured versus intrinsic emission, the EBL photon density can be derived. However, neither the intrinsic spectra nor the EBL is separately known~-~except their combined effect. Here we first present a flexible model-dependent optical depth method to study EBL by fitting the emission spectra of TeV BL Lacs objects via a one-zone leptonic synchrotron self-Compton model (SSC). We have little information about electron energy distributions (EEDs) in the jet, which is critically important to build spectral energy distributions (SEDs) in SSC scenario. Based on the current particle acceleration models, we use two types of EEDs, i,e., a power-law log-parabola (PLLP) EED and a broken power-law (BPL) EED to fit the observed spectra. We obtain that the upper limits of EBL density are around about 30 n W m$^{-2}$ sr$^{-1}$, which are similar to the published measurement. Furthermore, we propose an unprecedented method to test radiation mechanisms involved in TeV objects by simply comparing the reduced EBL density with the limit obtained by galaxy counts, and demonstrate that for some BL Lacs, at least, the one-zone SSC model should be reconsidered.
