球状星团核心的高分辨率X射线成像: 47Tuc中的紧二进制星体
J E Grindlay1, C Heinke, P D Edmonds
1Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. josh@cfa.harvard.edu
概括
钱德拉X射线天文台拍摄了球状星团47Tucanae的图像,揭示了紧的二进制星体的密集群体. 大多数来源是毫秒脉冲星 (MSP) 和积聚的白矮星,而不是中子星.
科学领域:
- 天文学和天体物理学
- X射线天文学X射线天文学
- 恒星群体的群体
背景情况:
- 球状星团是密集的恒星系统,为研究紧物体群体提供独特的环境.
- 了解球状星团中的二进制星群对于恒星进化和动态至关重要.
研究的目的:
- 为了研究球状星团47图卡纳 (NGC 104) 的高恒星密度核心中紧的二进制星体的种群.
- 用高分辨率的X射线成像来描述星团内的X射线源的性质.
主要方法:
- 使用钱德拉X射线天文台 (70千秒曝光) 对47个图卡纳的深度X射线成像.
- 分析X射线的光谱和时间特征.
- 与毫秒脉冲星 (MSP) 的无线电观测和哈勃太空望远镜的光学识别进行交叉相关性.
主要成果:
- 在中央2'x2.5'范围内检测到至少108个微弱X射线源的集中集中群体.
- 所有15个已知的毫秒脉冲星 (MSP) 都被确定,其中13个由Chandra解决.
- 估计来源群体为>50%的MSP,~30%的白矮星,~15%的发光主序二进制星和2-3个静止的低质量X射线二进制星.
- 一个约470太阳质量的上限被放置在一个中心的增量黑洞上.
结论:
- 这项研究为球状星团提供了第一个X射线"颜色大小"图.
- 在47 Tucanae建立了对紧物体和二进制物种的全面普查.
- 结果挑战了MSP形成的传统模型,在密集的恒星环境中提出了替代途径.
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