Weak annihilation cusp inside the dark matter spike about a black hole
Weak annihilation cusp inside the dark matter spike about a black hole
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黑洞周围暗物质尖峰内的弱湮灭尖点
DOI：
10.1103/physrevd.93.123510
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发表时间：
2016
影响因子：
5
通讯作者：
Shelton, Jessie
中科院分区：
文献类型：
--
作者：
Shapiro, Stuart L.;Shelton, Jessie
我们重新研究了大质量黑洞周围球形密度尖峰中湮灭对无碰撞暗物质（DM）分布的影响。我们首先构建了一个非常简单的，教学，分析模型的各向同性相空间分布函数，占湮灭和再现的“弱尖”发现由瓦西里耶夫DM深内的尖峰，远离其边界。尖点处的DM密度随波湮灭而变化，即距中心黑洞的距离，而不是一个平坦的“平台”轮廓。然后，我们通过引入一个损失锥来扩展该模型，该损失锥解释了孔洞对DM颗粒的捕获。损失锥是通过一个边界条件来实现的，该边界条件去除了捕获轨道，从而得到各向异性分布函数。最后，我们通过积分玻尔兹曼方程来演化初始尖峰分布函数，以显示弱尖点如何随时间增长及其密度如何随时间减小。我们采用银河系核心的参数特征和典型的WIMP模型，分别讨论了前波和前波DM湮灭两种情况。尖点密度轮廓波湮灭是较弱的，变化一样，但仍然不是一个平坦的平台。
We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase space distribution function that accounts for annihilation and reproduces the “weak cusp” found by Vasiliev for DM deep within the spike and away from its boundaries. The DM density in the cusp varies asfor-wave annihilation, whereis the distance from the central black hole, and is not a flat “plateau” profile. We then extend this model by incorporating a loss cone that accounts for the capture of DM particles by the hole. The loss cone is implemented by a boundary condition that removes capture orbits, resulting in an anisotropic distribution function. Finally, we evolve an initial spike distribution function by integrating the Boltzmann equation to show how the weak cusp grows and its density decreases with time. We treat two cases, one for-wave and the other for-wave DM annihilation, adopting parameters characteristic of the Milky Way nuclear core and typical WIMP models for DM. The cusp density profile for-wave annihilation is weaker, varying like, but is still not a flat plateau.