Collaborative Research: Cosmic magnetic fields: origin, evolution, and signatures

合作研究：宇宙磁场：起源、演化和特征

• 批准号: 1109180
• 负责人: Tina Kahniashvili
• 金额: $ 45万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1109180&HistoricalAwards=false
• 关键词: Collaborative; Research; Cosmic; magnetic; fields

AST-1109180/1109275/1108790Kahniashvili/Ratra/KosowskyObservations show that galaxies have magnetic fields with a component that is coherent over a large fraction of the galaxy, with defined field strength and coherence scale. Understanding the origin of these fields is one of the more challenging questions of modern astrophysics. There are currently two pictures: a bottom-up (astrophysical) one, generating the seed field on smaller scales, and a top-down (cosmological) version, generating the seed field prior to galaxy formation on scales that are now large. This project aims to answer several relevant questions: (i) How and when was the magnetic field generated? (ii) How does it evolve during the expansion of the universe? (iii) Can the amplitude and statistical properties of this seed magnetic field explain the properties of the observed magnetic fields in large-scale structures? (iv) Is the seed magnetic field detectable through cosmological observations? And if so, (v) what are the observational constraints on such a primordial magnetic field?The interdisciplinary project divides into the following related parts: (1) determining intergalactic magnetic field limits from currently available data; (2) studying cosmological large-scale correlated magnetic field generation mechanisms; (3) numerically studying the evolution of the magnetic field during the expansion of the universe; (4) numerically studying seed magnetic field amplification and dynamics during galaxy formation; and (5) predicting observable signatures of a cosmological seed magnetic field. This unique team of experts will significantly improve the current understanding of the origin, evolution, observational limits, and predicted signatures, of a cosmic magnetic field. The research includes important work in high energy physics, data analysis and interpretation, numerical simulation of magnetohydrodynamic processes, and galaxy and early structure formation. Perhaps most importantly, there is a chance to establish that observations demand a cosmological magnetic field that cannot be generated by any mechanism operating within the confines of the Standard Model of particle physics.The educational aspects include the training of undergraduate and graduate students. A vigorous education and public outreach program involves the North Central Kansas Astronomical Society, the KSU Center for the Understanding of Origins, Theodore Roosevelt Elementary School (Manhattan, Kansas), Allegheny Observatory at the University of Pittsburgh, the Stanford University 'Splash!' events for high school students, and Pittsburg State University outreach events. And, as part of an international collaboration, the primary PI will conduct cosmology education sessions for undergraduate students at Abastumani Astrophysical Observatory, Georgia.

AST-1109180/1109275/1108790Kahniashvili/Ratra/Kosowsky 观测表明，星系的磁场在星系的大部分区域内是相干的，具有明确的场强和相干尺度。 了解这些场的起源是现代天体物理学中更具挑战性的问题之一。 目前有两张图片：一张自下而上（天体物理学）的图片，在较小的尺度上生成种子场，以及一张自上而下（宇宙学）的版本，在现在较大的尺度上生成星系形成之前的种子场。 该项目旨在回答几个相关问题：（i）磁场是如何以及何时产生的？ (ii) 在宇宙膨胀过程中它是如何演化的？ (iii) 该种子磁场的振幅和统计特性能否解释在大尺度结构中观测到的磁场的特性？ (iv) 种子磁场可以通过宇宙学观测检测到吗？如果是这样，（v）这样一个原始磁场的观测限制是什么？这个跨学科项目分为以下相关部分：（1）根据当前可用数据确定星系间磁场限制； （2）研究宇宙学大尺度相关磁场产生机制； （3）数值研究宇宙膨胀过程中磁场的演化； (4) 数值研究星系形成过程中种子磁场的放大和动力学； (5)预测宇宙种子磁场的可观测特征。 这个独特的专家团队将显着提高目前对宇宙磁场的起源、演化、观测极限和预测特征的理解。 该研究包括高能物理、数据分析和解释、磁流体动力学过程的数值模拟以及星系和早期结构形成方面的重要工作。 也许最重要的是，有机会证明观测需要宇宙磁场，而在粒子物理标准模型的范围内运行的任何机制都无法产生这种磁场。教育方面包括本科生和研究生的培训。 堪萨斯州中北部天文学会、堪萨斯州立大学起源理解中心、西奥多·罗斯福小学（堪萨斯州曼哈顿）、匹兹堡大学阿勒格尼天文台、斯坦福大学“Splash！”高中生活动和匹兹堡州立大学外展活动。 而且，作为国际合作的一部分，首席 PI 将为佐治亚州阿巴斯图马尼天体物理观测站的本科生举办宇宙学教育课程。