论文标题
高能量范围内蟹状星云的伽马射线通量凹陷
Gamma-ray flux depressions of the Crab nebula in the high-energy range
论文作者
论文摘要
敏捷和费米观测值发现的蟹状星云的巨型伽玛射线令人惊讶，并挑战了脉冲星云的现有模型。我们已经对10。5年的费米 - 拉特观察结果进行了分析（2008年8月至2019年2月），并研究了100-300 MEV范围内的螃蟹星云的变异性。除了耀斑之外，我们还发现了伽马射线通量的几个月凹陷，并确定了几种急剧下降的情况，在一周内，相对于其平均值，通量减少了数量级。数据中没有发现$ e> 10美元的GEV范围内的星云通量的统计显着变化。我们讨论了观察到的γ射线通量凹陷对螃蟹星云的同步发射模型的可能含义。
The giant gamma-ray flares of the Crab nebula discovered by AGILE and Fermi observatories came as a surprise and have challenged the existing models of pulsar wind nebulae. We have carried out an analysis of 10.5 years of Fermi-LAT observations (Aug 2008 -- Feb 2019) and investigated variability of the Crab nebula in the 100-300 MeV range. Besides the flares, we found several month long depressions of the gamma-ray flux and identified several cases of sharp flux drops, where during one week the flux decreased by an order of magnitude with respect to its average value. No statistically significant variations of the nebula flux in the $E>$10 GeV range were found in the data. We discuss possible implications of the observed gamma-ray flux depressions on the model of synchrotron emission of the Crab nebula.
