发表机构
College of Physics, Sichuan University; State Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences; University of Chinese Academy of Sciences; TIANFU Cosmic Ray Research Center（四川大学物理学院; 中国科学院高能物理研究所粒子天体物理国家重点实验室; 中国科学院大学; 天府宇宙线研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分析HAWC对Geminga晕的观测，提出两种解释高能谱截断的机制：PWN加速极限或扩散系数上升导致泄漏，并预测了可观测差异。
AI 中文摘要
伽马射线脉冲星晕的谱在数十TeV能量处表现出清晰的截断特征。本研究通过解释HAWC对Geminga晕的观测数据，探讨了谱截断的起源。最直接的解释是，该截断反映了中心脉冲星风云（PWN）对电子加速能力的上限。我们利用球对称扩散激波加速模型来模拟这一情景，其中PWN终止激波的上游尺度限制了最大能量。我们还提出了对截断的另一种解释：如果周围星际介质中的电子扩散系数在高能下迅速上升，目标源产生的高能伽马射线通量的相当一部分可能泄漏到分析区域之外，从而产生观测到的谱截断效应。两种解释均成功再现了Geminga晕的谱截断。同时，这两种情景对脉冲星晕谱截断的统计特性以及相应PWN的X射线谱特征做出了不同的预测，这些预测可通过进一步的观测来检验。
英文摘要
The spectra of gamma-ray pulsar halos exhibit a clear cutoff feature at tens of TeV. This work investigates the origin of the spectral cutoff by interpreting the HAWC data of the Geminga halo. The most straightforward interpretation is that the cutoff reflects the maximum electron acceleration capability of the central PWN. We model this scenario using spherically symmetric diffusive shock acceleration, where the upstream scale of the PWN termination shock limits the maximum energy. We also propose an alternative interpretation of the cutoff: if the electron diffusion coefficient in the surrounding interstellar medium rises rapidly at high energies, a substantial fraction of high-energy gamma-ray flux from the target source can leak outside the analysis region, producing an observed spectral cutoff effect. Both explanations successfully reproduce the spectral cutoff of the Geminga halo. Meanwhile, the two scenarios make distinct predictions on the statistical properties of pulsar halo spectral cutoffs and the X-ray spectral features of the corresponding PWNe, which may be tested through further observations.
