能量离子在地球的弓冲击上方自生而有效的加速
D L Turner1, L B Wilson2, T Z Liu3
1Space Sciences Department, The Aerospace Corporation, El Segundo, CA, USA. drew.l.turner@aero.org.
Nature
|September 14, 2018
概括
观测显示在地球的弓冲击热流异常可以加速太阳风离子接近1000千电子伏. 这种高效的过程,与费米加速相一致,可能会解决宇宙射线注入的问题.
科学领域:
- 太空物理
- 血物理
- 天体物理学
背景情况:
- 地球的弓冲击是超音速太阳风相互作用形成的无碰撞冲击.
- 离子前震包含像热流异常 (HFA) 这样的短暂现象.
- HFA是冲击反射离子的度,可能是加速粒子.
研究的目的:
- 在热流异常中观察和描述粒子加速.
- 研究HFA驱动粒子加速背后的机制.
- 评估HFA对能量粒子生成的贡献.
主要方法:
- 在现场观察热流异常事件.
- 分析太阳风离子特性和能量谱.
- 与第一阶费米加速模型进行比较.
主要成果:
- 观测到的太阳风离子在HFA内从1-10 keV加速到近1000 keV.
- 加速效率取决于离子质量和电荷状态.
- HFAs比典型的弓冲击加速产生更高能量的粒子.
结论:
- 在近平行弓冲击的HFA是高效的粒子加速器.
- 这种机制为宇宙射线的"注入问题"提供了潜在的解决方案.
- 在天体物理冲击中产生能量粒子时,前层岩层的短暂物质可能起着至关重要的作用.
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