当地的暗物质分布中的团和流
1University of California, Department of Astronomy and Astrophysics, Santa Cruz, California 95064, USA. diemand@ucolick.org
Nature
|August 8, 2008
概括
暗物质模拟揭示了银河系光环中的众多幸存的子星球和冷流. 这些子结构与观测到的矮星系相匹配,增强了马射线和宇宙射线的产生,影响了宇宙学模型.
科学领域:
- 宇宙学的宇宙学是什么?
- 天体物理学 天体物理学
- 计算物理 计算物理
背景情况:
- 寒冷暗物质模型中的宇宙结构形成涉及较小单元的层次融合.
- 之前的模拟表明,合并不完全,内部光环核心作为子光环存活下来.
- 解决银河系光环内部区域的子结构对于理解暗物质分布至关重要.
研究的目的:
- 为了研究模拟银河系光环的内部区域的暗物质基层结构.
- 分析幸存的暗物质团块 (subhalos) 和流的特性和影响.
- 评估基层结构对可观测现象的影响,如矮星系的形成,引力透镜和粒子天体物理学信号.
主要方法:
- 在冷暗物质宇宙学中进行了结构形成的高分辨率数值模拟.
- 专注于解决模拟银河系光环中的暗物质亚结构,包括缩的团块和流.
- 模拟结果与矮卫星星系和引力透镜现象的观测数据进行了比较.
主要成果:
- 在太阳圈附近确定了数百个缩的暗物质子星球和众多的冷流.
- 揭示了暗物质集群的碎形性质,在孤立的光环和亚光环中都有一致的底层结构和的密度配置.
- 发现subhalo属性与观测到的微弱,暗物质主导的矮卫星星系相匹配,并可以解释异常的引力透镜流量比率.
- 预测暗物质灭绝导致的马射线产生 (4-15倍) 显著提升,由于子星球的作用增加了局部宇宙射线的产生 (1.4-10倍).
结论:
- 模拟支持重要的暗物质基层结构的生存,即使是在内部光环中.
- 在解释矮卫星星系的丰富性和属性以及透镜观测方面,Subhalos发挥着至关重要的作用.
- 暗物质的子结构大大增强了来自暗物质消灭和宇宙射线生成的天体物理信号.
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