论文标题
JWST Transit Spectra II：限制气溶胶物种，颗粒大小的分布，温度和金属性，用于多云的系外行星
JWST Transit Spectra II: Constraining Aerosol Species, Particle-size Distributions, Temperature, and Metallicity for Cloudy Exoplanets
论文作者
论文摘要
JWST将首次提供从光学到中红外的连续波长覆盖中等分辨率的过境光谱。在本文中，我们说明了不同的气溶胶物种，尺寸分布和空间分布如何在JWST Transit Spectra中编码信息。我们使用MIE理论以及对气溶胶大小和空间分布的几种灵活处理来执行参数敏感性研究，计算过境贡献函数，计算Jacobians和Markov Chain Chain Monte Monte Carlo检索参数。 JWST的更广泛的波长覆盖范围可能包括足够的非灰色气溶胶行为，以恢复有关物种的信息和颗粒的尺寸分布，尤其是在存在由气溶胶引起的不同共振特征时。在JWST波长范围内，光学和中红外通常提供有关0.1-1 $ $ M尺寸的气溶胶的信息，而近红外至中红外波长通常会提供有关气体吸收的信息，即使存在气溶胶。即使当前可观察到的光谱的光学和NIR部分，红外的强烈气体吸收特征也通常仍然可见。对于气溶胶特性，温度和表面重力的某些组合，尽管存在气溶胶，但仍可以精确地测量金属性，但是比具有相似特性的清晰大气相比，多云或朦胧大气的回试金属性的精度明显低。以身体动机的方式将气溶胶特性与大气金属性和温度联系起来的未来努力最终将使人们能够在多云，朦胧的系外行星大气中对过程有强烈的物理理解。
JWST will provide moderate resolution transit spectra with continuous wavelength coverage from the optical to the mid-infrared for the first time. In this paper, we illustrate how different aerosol species, size-distributions, and spatial distributions encode information in JWST transit spectra. We use the transit spectral modeling code METIS, along with Mie theory and several flexible treatments of aerosol size and spatial distributions to perform parameter sensitivity studies, calculate transit contribution functions, compute Jacobians, and retrieve parameters with Markov Chain Monte Carlo. The broader wavelength coverage of JWST will likely encompass enough non-gray aerosol behavior to recover information about the species and size-distribution of particles, especially if distinct resonance features arising from the aerosols are present. Within the JWST wavelength range, the optical and mid-infrared typically provide information about 0.1-1 $μ$m sized aerosols, while the near-infrared to mid-infrared wavelengths usually provide information about gaseous absorption, even if aerosols are present. Strong gaseous absorption features in the infrared often remain visible, even when clouds and hazes are flattening the optical and NIR portion of the spectrum that is currently observable. For some combinations of aerosol properties, temperature, and surface gravity, one can make a precise measure of metallicity despite the presence of aerosols, but more often the retrieved metallicity of a cloudy or hazy atmosphere has significantly lower precision than for a clear atmosphere with otherwise similar properties. Future efforts to securely link aerosol properties to atmospheric metallicity and temperature in a physically motivated manner will ultimately enable a robust physical understanding of the processes at play in cloudy, hazy exoplanet atmospheres.
