RUI: Multi-wavelength Spectroscopic and Spectropolarimetric Diagnostics of the Solar Atmosphere

RUI：太阳大气的多波长光谱和分光偏振诊断

基本信息

批准号：
2050340
负责人：
Debi Prasad Choudhary
金额：
$ 38.88万
依托单位：
The University Corporation, Northridge
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-15 至 2025-03-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2050340&HistoricalAwards=false
关键词：
RUI Multi wavelength Spectroscopic Spectropolarimetric

项目摘要

This 3-year project aims to develop data analysis techniques to infer the thermodynamic and magnetic structure of the solar atmosphere from the photosphere to a height of about 2-5 Mm using simultaneous multi-wavelength observations of spectral lines formed at different heights. Many current analysis approaches yield only simplified results instead of stratifications of physical properties. The project will develop an automatic, semi-empirical method to convert such results of lower complexity to atmospheric stratifications wherever they cannot be directly derived from an inversion of spectra. The method will be tested on observations of sunspots, where additional constraints on the magnetic field topology, connectivity and the gas density are available from the well-organized spatial structuring and magnetic field extrapolations. The results will enable one to address nearly all currently open questions in relation to the lower solar atmosphere, e.g., understanding the fine-structure and the properties of mass flows and oscillations inside sunspots from deep in the photosphere to the chromosphere. This will add to our understanding of the basic properties of sunspots, which are some of the most enigmatic objects in astrophysics. Sunspots are an integral part of late-type stars, play a vital role in stellar evolution and can influence life-supporting exoplanets including the Earth through space weather events that are rooted in sunspots and the active regions that host them. The method to infer the thermodynamic and magnetic structure of the solar atmosphere will be based on a piece-wise analysis of different photospheric and chromospheric spectral lines with already available inversion codes and the additional tools developed during the project. For any spectral line where current analysis methods do not provide stratifications of physical parameters of the solar atmosphere, e.g., the prominent chromospheric spectral line of neutral Hydrogen Alpha at 656 nm, a semi-empirical method using external constraints from magnetic field extrapolations will be employed to convert the results retrieved from a simplified modeling of the radiative transfer to stratifications. A major effort will be to consistently convert and combine the stratifications from different height regimes into a single atmospheric stratification of all relevant thermodynamic and magnetic parameters from 0 to about 5 Mm in the solar atmosphere. The resulting atmospheric model is expected to be in hydrostatic equilibrium, to provide all physical parameters on a geometrical height scale and to reproduce all observed spectral lines when a spectral synthesis of the model atmosphere is executed. A successful demonstration of the reliability of the approach on sunspot observations, where additional constraints are available because of the spatial continuity of the magnetic field topology, will allow one to decide on its suitability for observations of arbitrary solar targets. Any scientific question that requires accurate physical properties of the lower solar atmosphere can potentially be addressed with the results of the analysis approach. The tool developed through this project will be freely available to the community of solar researchers and will help in fully exploiting the observations with the NSF’s 4-meter class Daniel K. Inouye Solar Telescope. The participation of underrepresented students at California State University Northridge to both analyze and visualize the high-resolution spectropolarimetric data will prepare a future generation of the scientific workforce in solar physics. The research and EPO agenda of this 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.

这个为期3年的项目旨在开发数据分析技术，以使用在不同高度下形成的光谱线的简单多波长观测来推断从光球到大约2-5 mm的热力学和磁性结构。许多当前的分析方法仅产生简化的结果，而不是物理特性的分层。该项目将开发一种自动，半经验的方法，以将这种复杂性较低的结果转化为大气分层，无论它们不能直接从光谱反转。该方法将在观察结果上进行测试，其中磁场拓扑，连通性和气体密度的其他约束可从组织良好的空间结构和磁场外推提供。结果将使人们能够解决与较低太阳大气有关的几乎所有目前的打开问题，例如，了解从光电球深处到染色体的日晒内部的质量结构和质量流和振荡的特性。这将增加我们对黑子的基本特性的理解，黑子是天体物理学中一些最神秘的对象。黑子是晚期恒星不可或缺的一部分，在恒星进化中起着至关重要的作用，可以通过植根于黑子和托管的活跃地区的太空天气事件来影响施支持生命的外部活动。推断太阳大气的热力学和磁性结构的方法将基于对不同的光球和色球光谱线的零件分析，并具有已经可用的反转代码以及项目期间开发的其他工具。对于任何光谱线，当前分析方法不提供太阳大气的物理参数的分层，例如，在656 nm处的中性氢α的突出的染色体光谱线，一种使用磁场外部约束的半经验方法将采用从磁场挤压中进行的外部约束，以从简化的放射性模型转移到层次的模型中转化结果。一个主要的努力是将不同高度方案的分层始终转换为所有相关热力学和磁参数的单个大气层分层，从0到太阳大气中的0 mm约5 mm。预计所得的大气模型将处于静水平衡状态，在执行模型大气的光谱合成时，在几何高度尺度上提供所有物理参数，并重现所有观察到的光谱线。由于磁场拓扑的空间连续性，可以成功证明该方法在黑子观测上的可靠性，其中有其他约束，将使人们可以决定其适合观察任意太阳能目标的能力。分析方法的结果可能会解决任何需要较低太阳大气的准确物理特性的科学问题。通过该项目开发的工具将免费提供给太阳能研究人员的社区，并将有助于通过NSF的4米级丹尼尔·K·伊诺耶·索拉（Daniel K. Inouye Solar Telescope）充分利用观察结果。加利福尼亚州立大学诺斯里奇（Northridge）的代表性不足的学生参与分析和可视化高分辨率光谱学数据将为未来的太阳能物理学科学劳动力做好准备。该项目的研究和EPO AGEDA支持AGS分部在发现，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，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估的评估来支持的。