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arXiv 0908.1236astro-ph.HE
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银河漫射γ射线-基于宇宙电子能谱新测量的重新计算

Galactic diffuse gamma rays --- recalculation based on the new measurements of cosmic electron spectrum

Juan Zhang, Qiang Yuan, Xiao-Jun Bi

摘要:

在这项工作中,我们重新审视了全天银河弥漫$γ$ -射线辐射考虑到新的测量宇宙射线电子/正电子谱的PAMELA,ATIC和费米,这表明超出预期的流量在传统的模型中的宇宙电子/正电子过剩。由于额外电子/正电子的来源尚不清楚,我们考虑三种不同的情况来解释过量:天体物理来源,如银河系天体,暗物质衰变和湮灭。此外,还采用了Fermi-LAT中银河系外扩散$γ$射线的新结果。与费米-LAT观测相比,没有新来源的背景宇宙射线给出较低的漫射$γ$射线,这与先前的分析一致。天体物理源的方案预测扩散的$γ$ -射线与背景的差异很小。费米扩散$γ$射线数据不支持具有$τ^{\pm}$终态的暗物质湮灭模型,而衰减暗物质场景只有很少的约束。此外,由于终态辐射,在暗物质的漫射$γ$射线谱的较高能量($\sim$ TeV)处,这些总是一个凸起。最后,我们发现,费米-LAT扩散$γ$射线数据可以通过简单地扩大电子光谱的归一化而不引入任何新的来源来解释,这可能表明,在给定精确的背景估计的情况下,当前对暗物质模型的约束可以强得多。

英文摘要:

In this work, we revisit the all-sky Galactic diffuse $γ$-ray emission taking into account the new measurements of cosmic ray electron/positron spectrum by PAMELA, ATIC and Fermi, which show excesses of cosmic electrons/positrons beyond the expected fluxes in the conventional model. Since the origins of the extra electrons/positrons are not clear, we consider three different scenarios to account for the excesses: the astrophysical sources such as the Galactic pulsars, dark matter decay and annihilation. Further, new results from Fermi-LAT of the (extra-)Galactic diffuse $γ$-ray are adopted. The background cosmic rays without the new sources give lower diffuse $γ$ rays compared to Fermi-LAT observation, which is consistent with previous analysis. The scenario with astrophysical sources predicts diffuse $γ$-rays with little difference with the background. The dark matter annihilation models with $τ^{\pm}$ final state are disfavored by the Fermi diffuse $γ$-ray data, while there are only few constraints on the decaying dark matter scenario. Furthermore, these is always a bump at higher energies ($\sim$ TeV) of the diffuse $γ$-ray spectra for the dark matter scenarios due to final state radiation. Finally we find that the Fermi-LAT diffuse $γ$-ray data can be explained by simply enlarging the normalization of the electron spectrum without introduce any new sources, which may indicate that the current constraints on the dark matter models can be much stronger given a precise background estimate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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