Dark matter constraints from dwarf galaxies with data-driven J-factors
Dark matter constraints from dwarf galaxies with data-driven J-factors
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DOI：
10.1088/1475-7516/2020/09/004
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发表时间：
2020-09-01
影响因子：
6.4
通讯作者：
Zaldivar, Bryan
中科院分区：
文献类型：
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作者：
Alvarez, Alexandre;Calore, Francesca;Zaldivar, Bryan
我们提出了一个最新的分析的伽马射线通量从经典矮球状星系的方向，推导出新的约束WIMP暗物质（DM）湮灭使用十年的费米-LAT数据。在主要的新奇之处，我们推断的侏儒的J-因素，包括新的观察，而不施加任何先验参数配置文件的DM分布。虽然从统计上与更传统的参数化得到的结果兼容，这个过程减少了对数据施加的理论偏差。此外，我们保留了完整的数据驱动的形状的J-因子的经验概率分布时，设置限制DM，而不强加对数正态性，通常是这样做的。结合数据驱动的J因子，我们改进了一种新的方法，用于估计矮位置处天体物理背景的概率分布函数[1]，完全描绘背景不确定性。我们发现，对于大多数“经典”的矮星，背景系统的不确定性占主导地位的不确定性对他们的J-因素。J因子和D因子的原始分布（后者类似于衰减DM的J因子）可应要求提供。
We present an updated analysis of the gamma-ray flux from the directions of classical dwarf spheroidal galaxies, deriving new constraints on WIMP dark matter (DM) annihilation using a decade of Fermi-LAT data. Among the major novelties, we infer the dwarfs' J-factors by including new observations without imposing any a priori parametric profile for the DM distribution. While statistically compatible with results obtained from more conventional parameterisations, this procedure reduces the theoretical bias imposed on the data. Furthermore, we retain the full data-driven shape of the J-factors' empirical probability distributions when setting limits on DM, without imposing log-normality as is typically done. In conjunction with the data-driven J-factors, we improve on a new method for estimating the probability distribution function of the astrophysical background at the dwarf position [1], fully profiling over background uncertainties. We show that, for most "classical" dwarfs, the background systematic uncertainty dominates over the uncertainty on their J-factors. Raw distributions of J- and D-factors (the latter being the analogous of J-factors for decaying DM) are available upon request.