Possible GeV Emission from TeV Blazars-猫眼课题宝

DOI：

10.1086/589326

发表时间：

2008-08

期刊：

The Astrophysical Journal

影响因子：

--

通讯作者：

中科院分区：

其他

文献类型：

--

作者：

C. Y. Yang;J. Fang;G. Lin;Li Zhang

我们提出了一个模型来解释TeV耀变体可能的GeV辐射。在这个模型中，TeV耀变体可能的GeV辐射可以由两个部分组成。一个是源成分，通过同步加速器自康普顿（SSC）机制在源中产生;另一个是外部成分，通过e±对与宇宙微波背景（CMB）的逆康普顿（IC）散射从源到我们的途中产生，其中e±是通过TeV耀变体发射的TeV伽马射线与漫射IR-UV背景的相互作用产生的。我们应用该模型来研究Mrk 501，这是一个强的TeV的发射体可能的GeV的发射。我们自洽地计算了1997年Mrk 501三次不同活动的这两个分量的高能γ射线谱。结果表明：（1）当星系际磁场（IGMF）强度不大于10−19 G时，外源分量的GeV γ射线辐射可以占主导地位;（2）外源分量的光子谱形状取决于观测到的变化时间和IGMF强度，特别是在GeV能量范围的较低部分;（3）TeV光子的通量水平决定了外部成分的光谱;（4）Mrk 501不同活动的GeV辐射应该可以被即将发射的GLAST卫星探测到。

We propose a model to account for possible GeV emission from TeV blazars. In this model, the possible GeV emission from a TeV blazar can consist of two components. One, the source component, is produced in the source through the synchrotron self-Compton (SSC) mechanism; the other, the external component, is produced on the way from the source to us by the inverse Compton (IC) scattering of e± pairs with the cosmic microwave background (CMB), where the e± are created through the interaction of TeV gamma rays emitted from the TeV blazar with the diffuse IR-UV background. We apply the model to study the possible GeV emission from Mrk 501, which is a strong TeV emitter. We calculate self-consistently the spectra of high-energy gamma rays of these two components for three different activities of Mrk 501 in 1997. Our results indicate that (1) the GeV gamma-ray emission of the external component can dominate that of the source component if the intergalactic magnetic field (IGMF) strength is not greater than 10−19 G; (2) the shape of the photon spectra of the external component depends on both the observed variation time and the IGMF strength, particularly in the lower part of GeV energy range; (3) the flux level of TeV photons determines that of the spectrum of the external component; and (4) GeV emission from different activity in Mrk 501 should be detectable by the upcoming satellite GLAST.