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在银河系中直接检测到微镜头
C Alcock1, R A Allsman, D R Alves
1Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Nature
|December 12, 2001
概括
科学家们在大麦哲伦云中使用恒星微透镜寻找大质量紧光环物体 (MACHOs). 他们直接拍摄了微镜头,确定它是附近的低质量恒星,提供了MACHOs的直接证据.
科学领域:
- 天文学和天体物理学
- 宇宙学的宇宙学是什么?
背景情况:
- 宇宙中暗物质的组成在很大程度上是未知的.
- 发光物质仅占总重子物质的25%左右.
- 大型紧光环物体 (MACHO) 是潜在的暗物质候选物体.
研究的目的:
- 为了确定银河系暗物质中由MACHOs组成的部分.
- 为了研究恒星微镜的潜力来检测MACHOs.
- 为了直接识别透镜对象来限制MACHO质量.
主要方法:
- 在大麦哲伦云 (LMC) 中进行了对恒星微镜头事件的调查.
- 分析了前景物体对LMC恒星的引力透镜.
- 利用直接成像来识别微镜头物体.
主要成果:
- 调查表明,MACHOs可能构成银河系光环的8-50%的重子质量.
- 一个微镜头事件被直接成像,揭示了镜头是附近的小质量恒星在银河系的盘.
- 这种识别可以直接确定镜头质量.
结论:
- 作为一个附近的恒星,微镜的直接成像与预期一致.
- 这种方法允许在微镜头事件中直接确定镜头质量.
- 未来对光环微透镜事件的完整分析将直接探讨MACHOs的性质.
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