EAGER: Novel Approach to Acceleration and Escape of Charged Particles at Interplanetary and Astrophysical Shock Waves

冲击时粒子加速的模型预计将为更好地理解100多年前发现的宇宙射线的起源铺平道路。 扩散冲击加速（DSA）的当前标准模型适用于理想的情况下，无限平面的冲击波阵面;加速的过程是自我维持的，如果粒子可以对比流动平流和返回到冲击进行进一步的加速。 如果粒子不能被限制在激波附近，那么DSA方法是不可行的。 这个为期一年的EAGER项目的主要重点是探索一种新的方法来解释不适合DSA范式的高能粒子的观测。 这种方法将包括分析和数值分析，以支持对航天器数据的解释。 该研究项目将产生一个先进的理论模型，可以解释地球附近的冲击测量，以及各种天体物理源的观测，包括脉冲星风星云，耀变体，超新星遗迹等。这个为期一年的EAGER项目旨在改变我们目前对行星际和天体物理冲击波中带电粒子加速的理解。 几个行星际激波事件表现出高能粒子的幂律谱被破坏。 这样的光谱落在标准扩散冲击加速度（DSA）模型的有效性范围之外，尽管在几种情况下观察到，迄今为止研究得很差。 该项目建立在先前解释天体物理源观测到的电磁辐射的努力之上-高能电子的对数抛物线光谱，而不是经验的多个幂律-这解释了蟹状星云在前所未有的广泛能量范围内的观测结果。 该项目团队位于亚利桑那大学，旨在确定产生对数抛物线光谱的物理条件，这将在该领域产生范式转变。 该小组将利用项目期间收集的新知识，向公众宣传空间气象的物理驱动因素及其影响。 EAGER项目的研究和EPO议程支持AGS部门在发现、学习、多样性和跨学科研究方面的战略目标。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The modelling of particle acceleration at shocks is expected to pave the path to improved understanding of the origin of cosmic-rays, which were discovered more than 100 years ago. The current standard model of Diffusive Shock Acceleration (DSA) applies to the case of ideal, infinitely planar shock front; the process of acceleration is self-sustained if particles can contrast the flow advection and return to the shock to undergo further acceleration. If particles cannot be confined in proximity of the shocks, then the DSA approach is not feasible. The main focus of this one-year EAGER project is to explore a novel approach to explain the observations of energetic particles that do not fit in the DSA paradigm. This approach will comprise both analytic and numerical analyses, which support the interpretation of spacecraft data. The research project will produce an advanced theoretical model that may explain the measurements of shocks near the Earth, as well as observations of a variety of astrophysical sources, including pulsar wind nebulae, blazars, supernova remnants, etc.This one-year EAGER project is aimed at transforming our present understanding of the acceleration of charged particles at interplanetary and astrophysical shock waves. Several interplanetary shock events exhibit broken power-law spectra of the energetic particles. Such spectra fall outside the regime of validity of the standard Diffusive Shock Acceleration (DSA) model and, despite observed in several cases, have been poorly studied to date. This project builds upon a previous effort to interpret the observed electromagnetic radiation from astrophysical sources -- a log-parabola spectrum of energetic electrons, instead of empirical, multiple power-laws -- that explains surprisingly well the observations of the Crab Nebula over an unprecedentedly broad energy range. The project team, which based at the University of Arizona, aims to determine the physical conditions that give rise to a log-parabola spectrum, which would yield a paradigm shift in the field. The team will use the new knowledge gathered during the project to educate the general public about the physical drivers of space weather and their impacts. The research and EPO agenda of this EAGER project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.