A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
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DOI：
10.1088/1475-7516/2012/08/007
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发表时间：
2012-04
影响因子：
6.4
通讯作者：
C. Weniger
中科院分区：
文献类型：
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作者：
C. Weniger
对宇宙射线通量中伽马射线线的观察将是宇宙中暗物质湮灭或衰变的确凿证据。我们在费米大面望远镜 (LAT) 的数据中提出了对此类特征的改进搜索，重点关注 20 至 300 GeV 之间的能量。除了更新 43 个月的数据外，我们还使用一种新的数据驱动技术来根据银河暗物质晕的轮廓选择优化的目标区域。在靠近银河系中心的区域，我们发现 Eγ ≈ 130 GeV 处的伽马射线线有 4.6σ 指示。当考虑到别处效应时，观察到的过量显着性为 3.2σ。如果用暗物质粒子湮灭成光子对来解释，当使用 Einasto 暗物质剖面时，观测结果意味着暗物质质量为 mχ = 129.8±2.4 +7−13 GeV，部分湮灭截面为 σvχχ → γγ = (1.27±0.32 +0.18−0.28) × 10−27cm3s−1。该信号的证据基于大约 50 个光子；需要几年的额外数据才能澄清其存在。
The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides updating to 43 months of data, we use a new data-driven technique to select optimized target regions depending on the profile of the Galactic dark matter halo. In regions close to the Galactic center, we find a 4.6σ indication for a gamma-ray line at Eγ ≈ 130 GeV. When taking into account the look-elsewhere effect the significance of the observed excess is 3.2σ. If interpreted in terms of dark matter particles annihilating into a photon pair, the observations imply a dark matter mass of mχ = 129.8±2.4 +7−13 GeV and a partial annihilation cross-section of σvχχ → γγ = (1.27±0.32 +0.18−0.28) × 10−27cm3s−1 when using the Einasto dark matter profile. The evidence for the signal is based on about 50 photons; it will take a few years of additional data to clarify its existence.