利用GeV-TeV伽马射线观测约束中年超新星遗迹中的宇宙射线加速与逃逸
Constraining Cosmic-Ray Acceleration and Escape in Middle-Aged Supernova Remnants with GeV-TeV Gamma-Ray Observations
- Southwest Jiaotong University（西南交通大学）
- Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）
- Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过对四个中年超新星遗迹的伽马射线辐射开展时变研究，结合多望远镜观测，约束了宇宙射线加速与逃逸参数，揭示逃逸宇宙射线对其甚高能辐射及中微子通量的重要影响。
AI中文摘要：
本研究对四个具有代表性的中年超新星遗迹（SNR）——W51C、IC~443、W44、W28的伽马射线辐射开展了系统性的时变研究，同时考虑了遗迹壳层内的宇宙射线（CR）以及逃逸后与周围分子云相互作用的CR。我们将研究结果与Fermi-LAT、H.E.S.S.、MAGIC及LHAASO的GeV-TeV伽马射线观测数据进行对比，其中还包括对W28相关的A、B区域Fermi-LAT数据的专项分析。研究发现，观测到的能谱更支持较陡的CR注入能谱，其指数α约为4.2至4.3，质子最大能量约为100至300 TeV，扩散系数低于银河系平均值，CR加速效率为百分之几到百分之几十。特别地，LHAASO探测到的W51C甚高能（VHE）辐射可由逃逸CR与附近分子云的相互作用更自然地解释。我们还研究了逃逸CR对IC~443、W44和W28的VHE辐射的贡献，进一步证明逃逸CR可大幅提升中年SNR的TeV中微子通量，增强其作为潜在中微子源的前景。这些结果为中年SNR中的CR加速与逃逸提供了新的约束，并凸显了逃逸CR在塑造其高能伽马射线和中微子辐射中的重要作用。
英文摘要：
In this work, we perform a systematic, time-dependent study of the gamma-ray emission from four representative middle-aged SNRs (W51C, IC~443, W44, W28), incorporating both CRs within the remnant shells and escaped CRs interacting with surrounding molecular clouds. We compare our results with GeV--TeV gamma-ray observations from Fermi-LAT, H.E.S.S., MAGIC, and LHAASO, including a dedicated analysis of the Fermi-LAT data for regions A and B associated with W28. We find that the observed spectra favor steeper CR injection spectra with indices of \(α\sim4.2\)--\(4.3\), maximum proton energies of $\sim$ \(100\)--\(300\) TeV, diffusion coefficients below the Galactic average, and CR acceleration efficiencies from a few to tens of percent. In particular, the VHE emission detected by LHAASO from W51C is more naturally explained by escaped CRs interacting with a nearby molecular cloud. We also investigate the contribution of escaped CRs to the VHE emission from IC~443, W44, and W28. We further demonstrate that escaped CRs can substantially enhance the TeV neutrino flux from middle-aged SNRs, improving their prospects as potential neutrino sources. These results provide new constraints on CR acceleration and escape in middle-aged SNRs and highlight the important role of escaped CRs in shaping their high-energy gamma-ray and neutrino emission.
