Collaborative Research: Optimized frequency-domain analysis for astronomical time series

合作研究：天文时间序列的优化频域分析

• 批准号: 2307978
• 负责人: Sarah Dodson-Robinson
• 金额: $ 58.74万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307978&HistoricalAwards=false
• 关键词: Collaborative; Research; Optimized; frequency; domain

Earth-like planet searches are underway which can measure the motion of small planets around distant stars. However, investments in these instruments will not meet their full potential without advances in computer software. Through a three year award, a team led by the Universities of Delaware and Chicago will adapt a time domain data analysis tool previously used for health science and solar science for astronomy. Developing new analysis methods will save telescope time that costs tens of thousands of dollars per night by reducing the number of observations needed and increasing telescope efficiency. Students will be involved in the planet searches. The Team's goals are to involve physics and astronomy majors with all levels of academic preparation in planet searches and to create a supportive environment in which students can seek help from a faculty, scholars, and each other. While the Lomb-Scargle periodogram is foundational to astronomy, it has a significant short-coming: its variance does not decrease as more data are acquired. Statisticians have a 60-year history of developing variance-suppressing power spectrum estimators, but most are not used in astronomy because they are formulated for time series with uniform observing cadence and without seasonal or daily gaps. The team will mitigate the false-positive and bias problems of the Lomb-Scargle periodogram by adapting the multitaper power spectrum estimator for ground-based astronomical time series. They will present multitaper Magnitude-Squared Coherence (MSC) as a diagnostic of oscillations that manifest jointly in two or more observables. MSC between activity indicators and radial velocity is a powerful tool for identifying stellar rotation and harmonics, which have been responsible for many false positive planet detections. They will introduce a non-multitaper version of complex demodulation for ground-based time series. Complex demodulation, a local Fourier decomposition that reconstructs the long-period component of two coupled oscillations, can distinguish activity-modulated stellar signals from non-modulated planetary signals and recover full-phase rotation signals from observations of pulsating stars. This award funds development of the Oscillation Recognition and CAtegorization Software (ORCAS) package, which will contain python and Julia implementations of our frequency-domain methods. ORCAS will be sustainably hosted on bitbucket and registered with the Astrophysical Source Code Library. The methods developed can be applied to planet hunting, seismology, paleoclimatology, genetics, laser Doppler velocimetry, and the Rubin Observatory Legacy Survey of Space and Time.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.

类地行星搜索正在进行中，可以测量遥远恒星周围小行星的运动。然而，如果没有计算机软件的进步，对这些仪器的投资将无法充分发挥其潜力。通过为期三年的奖励，由特拉华大学和芝加哥大学领导的团队将把以前用于健康科学和太阳科学的时域数据分析工具应用于天文学。开发新的分析方法将通过减少所需的观测次数并提高望远镜效率来节省每晚花费数万美元的望远镜时间。学生将参与行星搜索。该团队的目标是让物理和天文学专业的学生参与行星搜索的各个层次的学术准备，并创造一个支持性的环境，让学生可以向教师、学者和彼此寻求帮助。虽然 Lomb-Scargle 周期图是天文学的基础，但它有一个显着的缺点：它的方差不会随着获取更多数据而减少。统计学家开发方差抑制功率谱估计器已有 60 年的历史，但大多数并未用于天文学，因为它们是针对具有统一观测节奏且没有季节或每日间隙的时间序列制定的。该团队将通过针对地面天文时间序列采用多锥功率谱估计器来减轻 Lomb-Scargle 周期图的误报和偏差问题。他们将提出多锥度平方相干性（MSC）作为对两个或多个可观测值共同显现的振荡的诊断。活动指示器和径向速度之间的 MSC 是识别恒星旋转和谐波的强大工具，这导致了许多行星检测的误报。他们将为地面时间序列引入复杂解调的非多锥版本。复数解调是一种局部傅立叶分解，可重建两个耦合振荡的长周期分量，可以区分活动调制的恒星信号与非调制的行星信号，并从脉动恒星的观测中恢复全相位旋转信号。该奖项资助振荡识别和 CAtgorization 软件 (ORCAS) 软件包的开发，该软件包将包含我们频域方法的 python 和 Julia 实现。 ORCAS 将持续托管在 bitbucket 上，并在天体物理源代码库中注册。开发的方法可应用于行星搜寻、地震学、古气候学、遗传学、激光多普勒测速以及鲁宾天文台遗产时空调查。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力评估进行评估，认为值得支持。优点和更广泛的影响审查标准。