Temporal Variability of the X-Ray Emission of the Crab Nebula Torus
Temporal Variability of the X-Ray Emission of the Crab Nebula Torus
复制标题
蟹状星云环面 X 射线发射的时间变化
DOI：
10.1086/306562
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
B. Aschenbach
中科院分区：
文献类型：
--
作者：
C. Greiveldinger;B. Aschenbach
我们提供 ROSAT HRI 对蟹状星云 1991 年 3 月至 1997 年 3 月 6 年间的观测结果。观测结果的比较表明，星云的发射率存在显着（>10 σ）差异，速率约为 yr-1 的 2%。这些差异仅限于相当大的（≳25“×25”）、明确的区域。其中一个区域与南极流出的末端重合，而其他区域则与脉冲星周围的环面重合。各个地区的时间历程不同，但总体呈现计数率的单调变化，有的增加，有的减少。对观测到的行为的一个可能的解释是，在6年的观测中，激波通过后相对论性风的径向整体运动减慢了10%-20%。
We present ROSAT HRI observations of the Crab Nebula spanning the 6 years from 1991 March to 1997 March. A comparison of the observations reveals that there are significant (>10 σ) differences in the emission from the nebula at a rate of ~2% yr-1. These differences are confined to rather large (≳25″ × 25″), well-defined regions. One region is coincident with the end of the southern polar outflow, while the others are coincident with the torus surrounding the pulsar. The various regions have different time histories, but they generally show a monotonic change in count rate, some increasing and others decreasing. A possible explanation for the observed behavior is that the radial bulk motion of the relativistic wind after shock passage has slowed by 10%-20% over the 6 years of observations.