Gamma radiation from the Crab Nebula above 35 MeV
Gamma radiation from the Crab Nebula above 35 MeV
复制标题
来自蟹状星云的伽马辐射高于 35 MeV
作者：
D. Kniffen;R. Hartman;D. Thompson;G. F. Bignami;G. F. Bignami;C. Fichtel;T. Tumer;H. Ögelman
从蟹状星云观测到的电磁辐射至少达到1 GeV（参考文献1），可能高达1012 eV（参考文献2和3）。蟹状星云在强x射线源中是独一无二的，因为在低能量范围（1-10 keV）的主要成分几乎没有时间变化。在x射线区观测到来自NP0532的一个小的脉冲分量（在10 keV时小于10%），但其相对于恒定分量的强度随着x射线能量的增加而增加。对蟹状星云在15-100 MeV范围内的伽马射线观测得出了相当不确定的结果，报道的上限4,5和通量6 - 10明显或几乎冲突。由于报告的强度在产生观测结果的气球实验中只能在大气背景上方勉强检测到，这似乎是可以理解的。
OBSERVATIONS of electromagnetic radiation from the Crab have been made to at least 1 GeV (ref. 1) and possibly as high as 1012 eV (refs 2 and 3). The Crab is unique among strong X-ray sources in that the major component in the low energy range (1–10 keV) shows little or no temporal variation. A small (≲ 10% at 10 keV) pulsed component from NP0532 is observed in the X-ray region, but its strength relative to the constant component increases with increasing X-ray energy. Gamma ray observations of the Crab in the 15–100 MeV range have yielded rather uncertain results with reported upper limits4,5 and fluxes6–10 in apparent or near conflict. As the reported intensities were just marginally detectable above atmospheric background with the balloon experiments which produced the observations, this seems understandable.