Collaborative Research: Polarimetric Imaging and Spectroscopy of the Corona from 500-1500nm during Total Solar Eclipses

合作研究：日全食期间 500-1500nm 日冕的偏振成像和光谱学

• 批准号: 0450096
• 负责人: Martina Arndt
• 金额: $ 2.56万
• 依托单位: BRIDGEWATER STATE UNIVERSITY
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0450096&HistoricalAwards=false
• 关键词: Collaborative; Research; Polarimetric; Imaging; Spectroscopy

The proposed four-year project will take advantage of unique opportunities offered by the total solar eclipses of 29 March 2006 (Libya) and 1 August 2008 (China-Russia) for imaging and spectroscopy of polarized coronal emissions at wavelengths spanning the visible to the near infrared. Polarized emission is a characteristic of some of the strongest coronal emission lines, while polarized fluorescence is a property of nanometer size dust particles. The near infrared polarimetric observations carried out by the PI during the eclipse of 21 June 2001 led to the serendipitous discovery of the signature of nanometer size dust particles in the inner corona. These 2001 observations also pointed to the potential existence of a discrete spectrum resulting from the fluorescence of these dust grains, and their spectrum is likely to be embedded within the spectrum of coronal ionic lines. By observing the next eclipses, the PI plans to infer the direction of the coronal magnetic field at different stages of the solar cycle, uncover the spectrum of nanometer size dust grains in the inner corona, and establish the relationship between interplanetary dust grains and the coronal magnetic field. In addition to the observations from Libya and China-Russia, simultaneous and identical observations will be made with the coronagraph in Hawaii. All the coronal observations will be compared with polarimetric laboratory measurements of fluorescence from silicon nanoparticles, which can be synthesized into stable and reproducible discrete sizes that fluoresce in the blue, green, yellow, and infrared part of the spectrum, under non-resonant UV or resonant excitation of their emission bands. Knowledge of the direction of the coronal field is critical for establishing the fraction of the solar magnetic flux that escapes into interplanetary space carrying the solar wind with it. Embedded in the solar wind, the interplanetary magnetic field shapes the environment of planets and defines the heliosphere. While the field also shapes cometary tails, it is likely to be responsible for the distribution of dust particles in the corona that may come from the sublimation of sun-grazing comets. The proposed program opens a new research direction by exploring the coupled signature of the coronal magnetic field direction and the fluorescence spectrum from nanoparticle dust grains in the inner corona. This effort will complement the laboratory experiments on polarized fluorescence from silicon nanoparticles.

拟议的四年期项目将利用2006年3月29日（利比亚）和2008年8月1日（中国-俄罗斯）的日全食提供的独特机会，对从可见光到近红外波长的偏振日冕辐射进行成像和光谱分析。偏振发射是一些最强日冕发射线的特征，而偏振荧光是纳米尺寸尘埃颗粒的特性。PI在2001年6月21日日食期间进行的近红外偏振观测偶然发现了内日冕中纳米尺寸尘埃颗粒的特征。这些2001年的观测还指出，这些尘埃颗粒的荧光可能会产生一个离散的光谱，它们的光谱很可能嵌入日冕离子线的光谱中。PI计划通过观察下一次日食来推断太阳周期不同阶段的日冕磁场方向，揭示内日冕中纳米尺寸尘埃颗粒的光谱，并建立行星际尘埃颗粒与日冕磁场之间的关系。除了利比亚和中俄的观测外，还将对夏威夷的日冕进行同步和相同的观测。所有的日冕观测结果将与来自硅纳米颗粒的荧光的偏振实验室测量结果进行比较，硅纳米颗粒可以合成为稳定且可重复的离散尺寸，在其发射带的非共振UV或共振激发下，在光谱的蓝色，绿色，黄色和红外部分发出荧光。 日冕磁场的方向对于确定携带太阳风逃逸到行星际空间的太阳磁通量的比例至关重要。嵌入太阳风中的行星际磁场塑造了行星的环境并定义了日光层。虽然磁场也塑造了彗星的尾巴，但它可能是日冕中尘埃颗粒分布的原因，这些尘埃颗粒可能来自掠日彗星的升华。该计划通过探索日冕磁场方向和内日冕中纳米颗粒尘埃颗粒的荧光光谱的耦合特征，开辟了一个新的研究方向。这项工作将补充实验室实验的偏振荧光从硅纳米粒子。