arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 0705.3854astro-ph
收藏

超新星遗迹中的强子γ射线

Hadronic Gamma Rays from Supernova Remnants

I. V. Moskalenko, T. A. Porter, M. A. Malkov, P. H. Diamond

摘要:

超新星遗迹(SNR)附近的气体云提供了一个pp碰撞的目标,导致随后的伽马射线发射通过中性π衰变。在预测信噪比甚高能γ射线辐射谱的模型中,通常假设加速粒子的环境谱指数接近-2。然而,如果气体云位于距离SNR冲击一定距离处,则该假设不一定正确。在这种情况下,与云相互作用的粒子是从激波泄漏的粒子,它们的光谱近似为单能,注入能量随着SNR的老化而逐渐减小。在GLAST能量范围内,粒子与气体云相互作用产生的伽马射线谱将比预期的要平坦,截止点由实验室坐标系中的π介子动量分布定义。我们评估从SNR冲击逃逸的粒子的通量,并将结果应用于HESS在银河系中心检测到的VHE漫发射。

英文摘要:

A gas cloud near a supernova remnant (SNR) provides a target for pp-collisions leading to subsequent gamma-ray emission through neutral pion decay. The assumption of a power-law ambient spectrum of accelerated particles with index near -2 is usually built into models predicting the spectra of very-high energy (VHE) gamma-ray emission from SNRs. However, if the gas cloud is located at some distance from the SNR shock, this assumption is not necessarily correct. In this case, the particles which interact with the cloud are those leaking from the shock and their spectrum is approximately monoenergetic with the injection energy gradually decreasing as the SNR ages. In the GLAST energy range the gamma-ray spectrum resulting from particle interactions with the gas cloud will be flatter than expected, with the cutoff defined by the pion momentum distribution in the laboratory frame. We evaluate the flux of particles escaping from a SNR shock and apply the results to the VHE diffuse emission detected by the HESS at the Galactic centre.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑