Stellar Contamination in Exoplanet Transmission Spectra

系外行星透射光谱中的恒星污染

• 批准号: 2757044
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2757044
• 关键词: Stellar; Contamination; Exoplanet; Transmission; Spectra

The purpose of the project is to constrain the contamination of exoplanet transmission spectra from stellar inhomogeneities (i.e., spots and faculae) in order that exoplanet atmospheric retrievals can be performed with greater accuracy. To begin, forward modelling of stellar atmospheres with magneto-hydrodynamic simulations will be done with a varying mean magnetic field and for different spectral types. The covering fraction and contrasts of the spots and faculae for each simulation will enable the contamination level to be known. The simulations will also explore the effect of having different active latitudes for spot and faculae emergence on the degree of contamination. Atmospheric retrievals will then be done to simulated transit data for a standard exoplanet transiting each of the stellar simulations. This will allow the effect of the known contamination on each of the derived transmission spectra to be constrained for varying magnetic field strength and stellar spectral type. The findings from this investigation will then be applied to real transit data.

该项目的目的是限制恒星不均匀(即光斑和光斑)对系外行星传输光谱的污染，以便能够更准确地进行系外行星大气反演。首先，将对不同光谱类型的平均磁场进行磁流体力学模拟，对恒星大气进行正演模拟。每个模拟的斑点和光斑的覆盖率和对比度将使我们能够知道污染水平。模拟还将探索具有不同活动纬度的黑子和光斑出现对污染程度的影响。然后，将对经过每一次恒星模拟的标准系外行星的模拟凌日数据进行大气检索。这将允许对于不同的磁场强度和恒星光谱类型来限制已知污染对每个导出的透射谱的影响。这项调查的结果随后将应用于真实的过境数据。