Glossary term: X射线
Description: X 射线是一种电磁波，其能量低于伽马射线，但高于紫外辐射。光谱中的 X 射线部分通常定义为波长范围在10 皮米到 10 纳米之间。这相当于大约 30 拍赫兹到 30 艾赫兹之间的频率。由此产生的光子（光粒子）的能量范围大约在 100 eV 到 100 keV 之间，这里用到的是粒子物理学中常用单位 "电子伏特"。
在天文学中，大量的 X 射线辐射通常来自高温（温度高于一百万开尔文）的气体或等离子体区域。例如我们太阳的日冕和其他恒星的星冕，以及致密天体周围的吸积盘：气体向中子星或黑洞坠落，在极热的盘中旋转，最后落到中心天体上或进入中心天体。超新星遗迹是另一类常见的天文 X 射线源：当一颗大质量恒星在其生命末期以超新星的形式爆发时，恒星的外层会被抛向太空。当这些被抛出的气体遇到周围的星际介质时，冲击效应会将碰撞区域的物质加热到很高的温度，从而产生 X 射线。
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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
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