来自脉冲星的脉冲马射线超过100GeV的检测
1Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027, USA.
Science (New York, N.Y.)
|October 8, 2011
概括
从脉冲星探测到的高能马射线挑战了目前的模型. 这些能量粒子起源于远离中子星的位置,因此需要对脉冲星发射机制进行新的解释.
科学领域:
- 高能天体物理学 高能天体物理学
- 脉冲星物理学的物理学
- 马射线天文学 马射线天文学
背景情况:
- 脉冲星是一个经过充分研究的中子星,在电磁频谱中发射.
- 以前对脉冲星在玛射线中的观测仅限于较低的能量.
- 了解脉冲星中的粒子加速和发射机制是天体物理学的一个关键挑战.
研究的目的:
- 报道从脉冲星探测到前所未有的高能脉冲玛射线的探测.
- 为了研究这种高能辐射的光谱特性.
- 为了限制粒子加速和脉冲星中的马射线生成的理论模型.
主要方法:
- 使用了非常有能量的辐射成像望远镜阵列系统 (VERITAS),是一系列大气切伦科夫望远镜.
- 分析了切伦科夫光信号来重建马射线事件.
- 对来自脉冲星的脉冲辐射进行了光谱分析.
主要成果:
- 探测到来自Crab脉冲星的脉冲性玛射线,其能量超过100千兆电子伏特 (GeV).
- 100兆电子伏特到400GeV之间的脉冲发射的光子光谱最好用一个破碎的功率定律来描述.
- 观测到的高能马射线不太可能来自曲率辐射,并暗示从中子星10个恒星半径之外的生产地点.
结论:
- 从Crab脉冲星探测到>100 GeV脉冲的玛射线与当前的脉冲星发射模型不一致.
- 观测到的光谱和推断出的辐射区域需要对脉冲星中的粒子加速和辐射理论进行修订.
- 未来的理论工作必须考虑这些高能观测,可能涉及从中子星更远处运行的机制.
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