AGS-FIRP Track 3: Solar Eclipse Observations with the Airborne Coronal Emission Surveyor (ACES)

该项目是Track-3的部署，目的是在2024年北美日全食期间，在NSF/NCAR湾流V （GV）上使用一种新的成像傅立叶变换光谱仪对日冕进行观测。目前正在美国国家科学基金会（NSF）授予的AGS-MRI #2117582上建造的机载日冕发射测量仪（ACES）将测量1-4 μm波长区域，寻找可能用于测量日冕磁场和大太阳半径等离子体诊断的可行候选线。ACES是一种新型焦平面仪器，由机载红外实验稳定平台（ASPIRE, AGS-MRI #1919809）启用，该平台于2021年投入使用，由GV观测。它建立在ASPIRE和机载红外光谱仪（AIR-Spec, AGS- MRI #1531549 & AGS #1822314）的成功基础上，扩大了太阳外层大气的热磁研究的红外窗口。日食活动和数据减少工作是基于观察2017年和2019年日全食的非常成功的AIR-Spec任务。部署完成后，该仪器将作为太阳物理界的资源交付给NCAR。两名REU学生和一名研究生将接受培训。该团队由职业生涯早期到中期的科学家和工程师组成，由一名女性PI领导。在GV上进行的6分钟调试观测期间，ACES将在14公里的高度进行观测，光谱分辨率为0.5 cm - 1，空间板比例尺为20”，视野范围为2000“×100”。这台仪器将搜寻20多条被禁止的离子线，包括镁、铝、硅、硫、氩、钙、铁和镍，其中至少有一半以前从未被观察到过。新的研究目标包括：确定最亮的光谱线；记录它们的宽度和线条轮廓的高阶属性；测量碰撞与辐射激发的贡献；记录上述所有变化作为观察到的特征和投影半径的函数。这些科学问题探讨了在1-4 μm范围内的发射线的诊断潜力、等离子体密度和温度随径向距离的变化、辐射和碰撞激发的比值随半径的变化以及日冕上元素丰度的变化。ACES的太阳能馈源将由ASPIRE提供，ASPIRE由美国国家科学基金会授予AGS-MRI #1919809建造，并于2021年12月投入使用。ASPIRE具有大光圈，高海拔和图像稳定性（1秒曝光6弧秒RMS），需要以高灵敏度测量红外日冕。该奖项反映了美国国家科学基金会的法定使命，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。

This project is a Track-3 deployment to commission a new imaging Fourier transform spectrometer with an observation of the solar corona from the NSF/NCAR Gulfstream V (GV) during the 2024 total solar eclipse across North America. The Airborne Coronal Emission Surveyor (ACES), currently under construction on NSF award AGS-MRI #2117582, will survey the 1–4 μm wavelength region to look for lines that may be viable candidates for measuring the coronal magnetic field and plasma diagnostics at large solar radii. ACES is a new focal plane instrument enabled by the Airborne Stabilized Platform for InfraRed Experiments (ASPIRE, AGS-MRI #1919809), commissioned in 2021 with observations from the GV. It builds on the success of ASPIRE and the Airborne InfraRed Spectrometer (AIR-Spec, AGS- MRI #1531549 & AGS #1822314) to expand the infrared window for thermal and magnetic studies of the Sun’s outer atmosphere. The eclipse campaign and data reduction effort are modeled on the very successful AIR-Spec missions to observe the 2017 and 2019 total solar eclipses. Following deployment, the instrument will be delivered to NCAR as a resource for the solar physics community. Two REU students and one graduate student will be trained. The team is a diverse group of early to mid-career scientists and engineers and is led by a female PI.During its six-minute commissioning observation from the GV, ACES will observe from an altitude of 14 km with a spectral resolution of 0.5 cm−1 and a spatial plate scale of 20" across a field of view of 2000"×100". The instrument will search for more than twenty forbidden lines of ionized magnesium, aluminum, silicon, sulfur, argon, calcium, iron, and nickel, at least half of which have never before been observed. The novel research goals include: identifying the brightest spectral lines; documenting their widths and higher order properties of the line profiles; measuring contributions from collisional versus radiative excitation; documenting the variations of all of the above as a function of the features observed and projected radius. The science questions probe the diagnostic potential of emission lines in the 1–4 μm range, the variation of plasma density and temperature with radial distance, the ratio of radiative to collisional excitation as a function of radius, and the variation of elemental abundances across the corona. The solar feed for ACES will be provided by ASPIRE, which was constructed with NSF award AGS-MRI #1919809 and commissioned in December 2021. ASPIRE enables the large aperture, high altitude, and image stability (6 arcsec RMS in a 1-s exposure) necessary to measure the infrared corona with high sensitivity.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.