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arXiv 0801.4673astro-ph
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来自宇宙学暗物质模拟的Gamma ray和中微子通量

Gamma ray and Neutrino fluxes from a cosmological dark matter simulation

E. Athanassoula, F. -S. Ling, E. Nezri, R. Teyssier

摘要:

在本文中,我们估计的γ射线和中微子流量来自暗物质湮灭在银河系框架提供了最近的N体视界模拟。我们首先研究了模拟的特点,突出了质量分布内的星系晕。一般的暗物质密度有一个典型的$r^{-3}$大半径的幂律,但内部的行为是不好的限制低于模拟的分辨率($\sim 200$ pc)。我们确定了团块和子团块,并分析了它们的分布,以及它们的内部结构。在团簇内部,幂律是相当普遍的,$r^{-2.5}$在外部,对于较小的半径,特别是对于轻的团簇,也有很强的不确定性。我们显示了一个全天地图的天体物理贡献的伽马射线或中微子通量在这个N体框架。使用相当独立的模型和一般假设的高能物理部分,我们评估可能的绝对通量,并显示一些基准区域的实验GLAST,EGRET,和一个km 3大小的扩展ANTARES一样的KM3NeT项目。虽然单个团块似乎无法探测到,但银河系中心区域是有希望的,GLAST可能对它的暗物质分布的几何形状和结构敏感。然而,通过km 3版本的ANTARES的检测由于更高的能量阈值而更具挑战性。我们还指出,缺乏决议离开subhalos的内部结构约束不良。使用相同的团簇光谱和质量分数,可以实现10阶的团簇光度提升,在子晕的内部具有更陡峭的轮廓。

英文摘要:

In this paper, we estimate the gamma-ray and neutrino fluxes coming from dark matter annihilation in a Milky Way framework provided by a recent N-BODY HORIZON simulation. We first study the characteristics of the simulation and highlight the mass distribution within the galactic halo. The general dark matter density has a typical $r^{-3}$ power law for large radii, but the inner behaviour is poorly constrained below the resolution of the simulation ($\sim 200$ pc). We identify clumps and subclumps and analyze their distribution, as well as their internal structure. Inside the clumps, the power law is rather universal, $r^{-2.5}$ in the outer part with again strong uncertainties for smaller radii, especially for light clumps. We show a full-sky map of the astrophysical contribution to the gamma-ray or neutrino fluxes in this N-body framework. Using quite model independent and general assumptions for the high energy physics part, we evaluate the possible absolute fluxes and show some benchmark regions for the experiments GLAST, EGRET, and a km3 size extension of ANTARES like the KM3NeT project. While individual clumps seem to be beyond detection reach, the galactic center region is promising and GLAST could be sensitive to the geometry and the structure of its dark matter distribution. The detection by a km3 version of ANTARES is, however, more challenging due to a higher energy threshold. We also point out that the lack of resolution leaves the inner structure of subhalos poorly constrained. Using the same clump spectrum and mass fraction, a clump luminosity boost of order ten can be achieved with a steeper profile in the inner part of the sub-halos.

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