arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2402.01048astro-ph.HE
收藏

超新星遗迹中可达到的最大能量:自洽模拟

Maximum energy achievable in supernova remnants: self-consistent simulations

Emily Simon, Damiano Caprioli, Colby Haggerty, Brian Reville

AI总结:

本研究针对斜激波与准垂直激波能否产生高能宇宙线的问题,采用带伪激波边界的低成本混合模拟,发现其可从激波漂移加速过渡到扩散激波加速并触发非共振混合不稳定性,或是高能宇宙线及能谱膝的重要成因。

摘要:

长期以来,人们认为超新星遗迹(SNRs)中的斜激波和准垂直构型无法有效地将离子注入扩散激波加速(DSA)过程,且最高能的银河系宇宙线(CRs)必定来自平行或准平行激波。然而,近期的三维动力学模拟表明,高倾角激波能够成功使粒子获得能量,并在上游区域产生放大的磁场。本研究旨在探究斜激波与准垂直激波中可产生的粒子最大能量,以及这类激波是否能够触发非共振混合不稳定性(NRHI)。我们提出了一种用于非相对论激波混合模拟的新型设置,该设置采用“伪激波”边界条件替代真实激波,可大幅降低计算成本,且能够运行足够长的时间以研究这类系统的晚期行为。我们的结果显示,斜激波与准垂直激波可能会从早期的激波漂移加速(SDA)阶段过渡到晚期的DSA阶段,使粒子先经历一段短暂的快速加速期,随后进入长期、自持的较慢能量增长阶段。此外,我们还发现了晚期上游区域会触发NRHI的证据。斜激波与准垂直激波可能是高能宇宙线的重要来源,甚至可能是宇宙线能谱膝的成因。

英文摘要:

It has been long believed that oblique and quasi-perpendicular configurations in supernova remnants (SNRs) were inefficient at injecting ions into diffusive shock acceleration (DSA), and that the highest energy Galactic cosmic rays (CRs) must come from parallel or quasi-parallel shocks. However, recent 3D kinetic simulations have shown that high-obliquity shocks can successfully energize particles and produce amplified magnetic fields in the upstream. We aim to investigate the maximum energy particles it is possible to produce in oblique and quasi-perpendicular shocks and whether they are capable of triggering the non-resonant hybrid instability (NRHI). We present a novel setup for hybrid simulations of non-relativistic shocks that use a "faux shock" boundary condition instead of a real shock to significantly reduce the computational cost and that can be run for long enough to study the late-time behaviors of these systems. Our results show that it may be possible for oblique and quasi-perpendicular shocks to transition from early periods of shock drift acceleration (SDA) into DSA at later times, giving particles a brief period of rapid acceleration followed by a long-duration, self-sustaining period of slower energy growth. Furthermore, we find evidence that the NRHI is triggered in the upstream at late times. Oblique and quasi-perpendicular shocks may be an important contributor to high energy CRs, potentially even responsible for the knee in the CR energy spectrum.

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。

↑