CONSTRAINTS ON THE GALACTIC HALO DARK MATTER FROM FERMI-LAT DIFFUSE MEASUREMENTS
CONSTRAINTS ON THE GALACTIC HALO DARK MATTER FROM FERMI-LAT DIFFUSE MEASUREMENTS
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DOI：
10.1088/0004-637x/761/2/91
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发表时间：
2010-12
期刊：
影响因子：
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通讯作者：
G. Zaharijas;A. Cuoco;Zhaoyu Yang;J. Conrad;for the Fermi-LAT collaboration
中科院分区：
文献类型：
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作者：
G. Zaharijas;A. Cuoco;Zhaoyu Yang;J. Conrad;for the Fermi-LAT collaboration
我们用费米大面积望远镜(LAT)对银河系晕区的弥散伽马射线发射进行了分析，以寻找暗物质湮灭或衰变的信号。在没有强暗物质信号的情况下，给出了约束条件。我们考虑在暗物质湮灭/衰变过程中直接产生的伽马射线和在湮灭/衰变过程中产生的e+/e−的逆康普顿散射产生的伽马射线。推导出的保守极限要求暗物质信号不超过观测到的弥散伽马射线发射。第二组更严格的限制是基于使用GALPROP代码对前景天体物理漫反射发射进行建模而得出的。使用轮廓似然公式考虑了扩散宇宙线晕高度、银河系中宇宙线源的分布、注入宇宙线电子能谱指数和星际气体柱密度等不确定因素，而控制宇宙线传播的参数是通过与当地宇宙线数据的拟合得到的。由此产生的极限影响了早期宇宙中暗物质热产生的粒子质量范围，并挑战了将帕梅拉/费米-拉特宇宙线异常解释为暗物质湮灭的解释。
We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope (LAT) in the Milky Way halo region, searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e+/e− produced in the annihilation/decay. Conservative limits are derived requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission. A second set of more stringent limits is derived based on modeling the foreground astrophysical diffuse emission using the GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the distribution of the cosmic-ray sources in the Galaxy, the index of the injection cosmic-ray electron spectrum, and the column density of the interstellar gas are taken into account using a profile likelihood formalism, while the parameters governing the cosmic-ray propagation have been derived from fits to local cosmic-ray data. The resulting limits impact the range of particle masses over which dark matter thermal production in the early universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as the annihilation of dark matter.