发表机构
School of Mathematics and Statistics, University of Glasgow; Department of Physics, University of Trento; Institute for Experimental and Applied Physics (IEAP), Christian-Albrechts-University of Kiel; Department of Physical and Earth Sciences, Sol Plaatje University; School of Physical and Chemical Sciences, North-West University; Centre for Space Research, North-West University（格拉斯哥大学数学与统计学院; 特伦托大学物理系; 基尔大学实验与应用物理研究所; 索尔·普拉塔杰大学物理与地球科学系; 西北大学物理与化学科学学院; 西北大学太空研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对2017年银河宇宙线通量下降，提出在CME主导期间允许垂直与平行扩散系数之比随时间变化，在保持谱拟合质量的同时恢复平均自由程的刚度排序，有效约束输运解。
AI 中文摘要
2017年下半年，随着第24太阳活动周接近极小期，利用AMS-02观测到了银河宇宙线（GCR）质子通量中一次显著的、依赖于刚度的下降事件。该事件由一系列强日冕物质抛射（CMEs）驱动。在本工作中，我们采用稳态Parker输运框架，并利用AMS-02观测约束参数，对这一时期GCR质子的调制进行了建模。将该事件视为纯长期调制区间，可获得与观测质子强度极好的一致性，但由此推断出的粒子平均自由程对刚度的依赖关系与基本湍流理论不符，相当于散射机制的有效反转。我们认为，这种行为源于高度灵活的输运参数化能够通过瞬变事件期间扩散系数的关联调整来再现综合调制特征。为解决这一不一致性，我们放宽了垂直与平行扩散系数之比与时间无关的常用假设，并在CME主导区间引入了该比值的物理上合理的减小。这一修改在保持谱拟合质量的同时，恢复了平均自由程预期的刚度排序。我们的结果表明，允许垂直与平行扩散系数之比随时间变化，为约束2017年下降期间的输运解提供了一种有效手段，并可能有助于解决其他GCR调制研究中报告的类似不一致性。
英文摘要
In the second half of 2017, as Solar Cycle 24 approached its minimum, a pronounced and rigidity-dependent depression in the galactic cosmic ray (GCR) proton flux was observed using AMS-02. This event was driven by a sequence of strong coronal mass ejections (CMEs). In this work, we model the modulation of GCR protons during this period using a steady-state Parker transport framework with parameters constrained by AMS-02 observations. Treating the event as a purely long-term modulation interval yields excellent agreement with the observed proton intensities, but implies an inferred rigidity dependence of particle mean free paths that is inconsistent with basic turbulence theory, corresponding to an effective inversion of the scattering regime. We argue that this behaviour arises from the ability of highly flexible transport parameterizations to reproduce integrated modulation signatures through correlated adjustments of diffusion coefficients during transient events. To address this inconsistency, we relax the commonly adopted assumption of a time-independent ratio of perpendicular to parallel diffusion coefficients and introduce a physically motivated reduction of this ratio during the CME-dominated interval. This modification preserves the quality of the spectral fits whilst restoring the expected rigidity ordering of mean free paths. Our results indicate that allowing the perpendicular-to-parallel diffusion ratio to vary in time provides an effective means of constraining transport solutions during the 2017 depression and may help to resolve similar inconsistencies reported in other GCR modulation studies.
CommentsTotal 18 pages, 7 Figures, Accepted, Astrophysical Journal
Journal refAstrophysical Journal, Vol. 1010, 8, 2026
