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arXiv 1010.5652astro-ph.HE
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银河系IV中三维cosmic-ray传播的一种可能方法。电子和电子感生γ射线

A possible approach to three-dimensional cosmic-ray propagation in the Galaxy IV. Electrons and electron-induced gamma-rays

T. Shibata, T. Ishikawa, S. Sekiguchi

摘要:

基于考虑与磁流体湍流碰撞引起的随机再加速的宇宙线扩散晕模型,研究了电子分量及其产生的扩散$γ$射线(D $γ$ 's)的行为.在这些研究中出现的银河系参数基本上是相同的强子CR组件中出现的,而我们还需要星际辐射场的信息,同时考虑到依赖于两个光子的能量,$E_{\scriptsize {ph}}$,和位置,$\vct{r}$。我们将计算结果与强子、电子和D $γ$的结果进行了比较,其中包括FERMI的最新结果,得到了两个显著的结果:1)电子能谱在1,TeV以下能量为$E_e^{-3}$,在500,GeV附近不表现出明显的能谱特征,与ATIC和PPB-BETS谱中出现的显著过剩相反,2)D $γ$谱中的EGRET GeV过量既不是由于天文起源(银河系中心的CR谱硬得多),也不是由于宇宙学起源(暗物质湮灭或衰变),而是由于仪器问题。然而,在本文中,我们把我们的兴趣,而保守的这三个组件之间的内部关系,使用{ \it共同}星系参数。我们发现,它们是在合理的和谐与对方的理论和实验的不确定性,除了电子异常的问题,而一些增强的D $γ$的出现在银河系高纬度与$|b| > 60^\circ$在GeV区域。

英文摘要:

Based on the diffusion-halo model for cosmic-ray (CR) propagation, including stochastic reacceleration due to collisions with hydromagnetic turbulence, we study the behavior of the electron component and the diffuse $γ$-rays (D$γ$'s) induced by them. The galactic parameters appearing in these studies are essentially the same as those appearing in the hadronic CR components, while we additionally need information on the interstellar radiation field, taking into account dependences on both the photon energy, $E_{\scriptsize {ph}}$, and the position, $\vct{r}$. We compare our numerical results with the data on hadrons, electrons and D$γ$'s, including the most recent results from FERMI, which gives two remarkable results; 1) the electron spectrum falls with energy as $E_e^{-3}$ up to 1\,TeV, and does not exhibit prominent spectral features around 500\,GeV, in contrast to the dramatic excess appearing in both ATIC and PPB-BETS spectra, and 2) the EGRET GeV-excess in the D$γ$ spectrum is due neither to an astronomical origin (much harder CR spectrum in the galactic center) nor a cosmological one (dark matter annihilation or decay), but due to an instrumental problem. In the present paper, however, we focus our interest rather conservatively upon the internal relation between these three components, using {\it common} galactic parameters. We find that they are in reasonable harmony with each other within both the theoretical and experimental uncertainties, apart from the electron-anomaly problem, while some enhancement of D$γ$'s appears in the high galactic latitude with $|b| > 60^\circ$ in the GeV region.

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