Search for photon-linelike signatures from dark matter annihilations with H.E.S.S.
Search for photon-linelike signatures from dark matter annihilations with H.E.S.S.
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DOI：
10.1103/physrevlett.110.041301
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发表时间：
2013-01
影响因子：
8.6
通讯作者：
A. Abramowski;F. Acero;F. Aharonian;A. Akhperjanian;G. Anton;S. Balenderan;A. Balzer;A. Barnacka-A.-Barnack
中科院分区：
文献类型：
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作者：
A. Abramowski;F. Acero;F. Aharonian;A. Akhperjanian;G. Anton;S. Balenderan;A. Balzer;A. Barnacka-A.-Barnack
由于空间中暗物质 (DM) 粒子的自湮灭或衰变，伽马射线线特征预计会出现在极高能量 (E(γ)>100 GeV) 域中。这样的信号很容易与天体物理γ射线源区分开来，后者在大多数情况下产生能量跨越几个数量级的连续光谱。使用 H.E.S.S. 收集的数据γ射线仪器，在银河系晕中心部分和河外观测的~ 500 GeV和~ 25 TeV之间的能量范围内获得了线状发射的上限，补充了费米-LAT仪器在较低能量下获得的最新限制。没有发现统计上显着的信号。对于单色γ射线线发射，银河晕中心部分和河外观测分别获得了(2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1)和(1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1)通量极限。对于 1 TeV 的 DM 粒子质量，基于银河 DM 晕密度剖面的 Einasto 参数化，速度平均 DM 湮没截面 ⟨σv⟩(χχ → γγ) 的极限达到 ∼ 10(-27) cm(3)s(-1)。
Gamma-ray line signatures can be expected in the very-high-energy (E(γ)>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical γ-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H.E.S.S. γ-ray instrument, upper limits on linelike emission are obtained in the energy range between ∼ 500 GeV and ∼ 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic γ-ray line emission, flux limits of (2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1) and (1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section ⟨σv⟩(χχ → γγ) reach ∼ 10(-27) cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile.