Double Gamma-ray Lines from Unassociated Fermi-LAT Sources
Double Gamma-ray Lines from Unassociated Fermi-LAT Sources
复制标题
来自非关联费米 LAT 源的双伽玛射线线
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
D. Finkbeiner
中科院分区：
文献类型：
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作者：
M. Su;D. Finkbeiner
长期以来，人们一直在寻找银河系中暗物质暗晕的伽马射线发射，作为暗物质粒子湮灭的标志。到目前为止，从晕下寻找伽马射线连续体一直是不成功的，而在没有线能量的先验知识的情况下，线搜索是困难的。根据最近在银河系中心111 GeV和129 GeV的线发射的声明，我们使用3.9年的LAT数据研究了第二费米LAT目录（2FGL）中无关联点源的共同添加的伽马射线谱。使用源事件类，我们发现在111 GeV和129 GeV的线的证据与3.3 sigma的局部意义的基础上保守估计的背景在E>135 GeV。以同样方式分析的其他2FGL源在111 GeV和129 GeV处没有显示线发射。线发射源大多在银河平面的30度范围内，尽管这种各向异性可能是一种选择效应。如果这些物体的双线发射被未来的数据证实，它将为银河系中心线信号确实来自暗物质湮灭的假设提供令人信服的支持。
Gamma ray emission from dark matter subhalos in the Milky Way has long been sought as a sign of dark matter particle annihilation. So far, searches for gamma-ray continuum from subhalos have been unsuccessful, and line searches are difficult without prior knowledge of the line energies. Guided by recent claims of line emission at 111 GeV and 129 GeV in the Galactic center, we examine the co-added gamma-ray spectrum of unassociated point sources in the Second Fermi-LAT catalog (2FGL) using 3.9 years of LAT data. Using the SOURCE event class, we find evidence for lines at 111 GeV and 129 GeV with a local significance of 3.3 sigma based on a conservative estimate of the background at E>135 GeV. Other 2FGL sources analyzed in the same way do not show line emission at 111 GeV and 129 GeV. The line-emitting sources are mostly within 30 degrees of the Galactic plane, although this anisotropy may be a selection effect. If the double-line emission from these objects is confirmed with future data, it will provide compelling support for the hypothesis that the Galactic center line signal is indeed from dark matter annihilation.