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

EAGER：行星际和天体物理冲击波中带电粒子加速和逃逸的新方法

• 批准号: 1850774
• 负责人: Federico Fraschetti
• 金额: $ 9.94万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-11-01 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1850774&HistoricalAwards=false
• 关键词: EAGER; Novel; Approach; Acceleration; Escape

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.

预计粒子加速度的建模有望为改善对宇宙射线起源的理解铺平道路，而宇宙射线是100多年前发现的。 当前的扩散冲击加速度（DSA）的标准模型适用于理想的无限平面冲击阵线的情况。如果粒子可以对比流量对流并恢复冲击以进行进一步加速，则加速过程是自我维持的。 如果不能将粒子限制在冲击的接近度中，则DSA方法是不可行的。 这个为期一年的项目的主要重点是探索一种新的方法来解释不适合DSA范式的能量颗粒的观察结果。 这种方法将既包括分析和数值分析，这些分析支持了航天器数据的解释。 该研究项目将产生一个先进的理论模型，该模型可以解释地球附近的冲击测量，并观察到各种天体物理来源，包括脉冲星风云，大型，超新星保证金等。这为期一年的渴望项目旨在改变我们目前对收费的smecterles shocks interplanetalsical and planephysical and plandopsalys and plastopersical and plastopersical and plastopersical and plastopersical and plastopsalys wav的理解。 几个行星际冲击事件显示出能量颗粒的断开幂律光谱。 这种光谱落在标准扩散冲击加速度（DSA）模型的有效性状态之外，尽管在几种情况下观察到，但对迄今为止的研究很少。 该项目基于先前的努力来解释天体物理来源的电磁辐射 - 一种能量电子的对数 - 帕托蛋白频谱，而不是经验性的多个幂律 - 令人惊讶地解释了蟹状星云的观察到前所未有的广泛能源范围。 总部位于亚利桑那大学的项目团队旨在确定产生对数parabola频谱的物理条件，这将在该领域产生范式转变。 该团队将利用项目期间收集的新知识来教育公众有关太空天气的物理驱动力及其影响。 该急切的项目的研究和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的法定任务，并被认为值得通过基金会的知识分子优点和更广泛的影响标准通过评估来进行评估。

项目成果

Effect of Acceleration and Escape of Energetic Particles on Spectral Steepening at Shocks

• DOI: 10.3847/1538-4357/abd699
• 发表时间: 2020-12
• 期刊: The Astrophysical Journal
• 作者: F. Fraschetti

The Stellar CME–Flare Relation: What Do Historic Observations Reveal?

• DOI: 10.3847/1538-4357/ab1b37
• 发表时间: 2019-04
• 期刊: The Astrophysical Journal
• 作者: S. Moschou;J. Drake;O. Cohen;J. D. Alvarado-G'omez;C. Garraffo;F. Fraschetti

The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 d

宜居带系外行星 TOI 700 d 的空间环境和大气焦耳加热

• DOI: 10.3847/1538-4357/ab9637
• 发表时间: 2020
• 期刊: The Astrophysical Journal
• 作者: Cohen, Ofer;Garraffo, C.;Moschou, Sofia-Paraskevi;Drake, Jeremy J.;Alvarado-Gómez, J. D.;Glocer, Alex;Fraschetti, Federico
• 通讯作者: Fraschetti, Federico

In Situ Measurement of the Energy Fraction in Suprathermal and Energetic Particles at ACE, Wind, and PSP Interplanetary Shocks

ACE、风和 PSP 行星际激波中超热和高能粒子能量分数的原位测量

• DOI: 10.3847/1538-4357/ac54af
• 发表时间: 2022
• 期刊: The Astrophysical Journal
• 作者: David, Liam;Fraschetti, Federico;Giacalone, Joe;Wimmer-Schweingruber, Robert F.;Berger, Lars;Lario, David
• 通讯作者: Lario, David

Stellar Energetic Particle Transport in the Turbulent and CME-disrupted Stellar Wind of AU Microscopii

AU Microscopii 湍流和 CME 扰乱的恒星风中的恒星高能粒子输运

• DOI: 10.3847/1538-4357/ac86d7
• 发表时间: 2022
• 期刊: The Astrophysical Journal
• 作者: Fraschetti, Federico;Alvarado-Gómez, Julián D.;Drake, Jeremy J.;Cohen, Ofer;Garraffo, Cecilia
• 通讯作者: Garraffo, Cecilia