论文标题
系外行星大气中的云和危险的温度趋势
A Temperature Trend for Clouds and Hazes in Exoplanets Atmospheres
论文作者
论文摘要
在近红外范围内使用哈勃太空望远镜（HST）观察到的系外行星大气的传输光谱（1.1-1.65 $μ$ m）经常显示出证据表明云和危险组合的某种组合。鉴定系外星云和HAZE的系统趋势对于理解大气成分和温度结构可能很重要。在这里，我们报告了使用来自62个系外行星的大型，均匀处理的HST/WFC3传输光谱样品对光谱调制的分析。光谱检索包括检测和表示组成脱离热化学平衡的气氛的能力。与严格清晰的大气相比，使用这种独特的目录并测量了光谱调制的衰减，我们确定了两个人群。一个是完全无云/无雾的温度范围，而另一个人群被确定为``部分云/hazes''，这是从大多数云/危险的趋势左右的趋势左右$ \ sim $ \ sim $ 1500〜k。我们还发现，经常存在部分透明的气溶胶成分，并且通常在整个大气柱上垂直分布。我们的发现还表明，虽然云和危险在系外行星大气中很常见，但大多数行星都具有一定程度的可检测光谱调制。此外，在我们目录中揭示的云和危险量最小的经验趋势是将云和危险降至1460.86K $^{+316} _ { - 405} $具有预测性的实用性，可以建模大规模的透射系外行星调查的性能，例如按照Ariel Mission的计划。在将来的JWST观测值的背景下，这种趋势也可以用于对给定来源进行基于概率的光谱调制预测。包括光学和/或更广泛的光谱覆盖物在内的未来观察结果对于进一步量化此处报告的趋势可能很有用。
The transmission spectra of exoplanet atmospheres observed with the Hubble Space Telescope (HST) in the near-infrared range (1.1-1.65$μ$m) frequently show evidence for some combination of clouds and hazes. Identification of systematic trends in exoplanet clouds and hazes is potentially important for understanding atmospheric composition and temperature structure. Here we report on the analysis of spectral modulation using a large, uniformly processed sample of HST/WFC3 transit spectra from 62 exoplanets. The spectral retrieval includes the capability to detect and represent atmospheres in which the composition departs from thermochemical equilibrium. By using this unique catalog and measuring the dampening of spectral modulations compared to strictly clear atmospheres, we identify two populations. One is completely cloud/haze free spanning a wide temperature range, while the other population, identified as ``Partial cloud/hazes'', follows a trend from mostly cloudy/hazy around 500~K to mostly clear at $\sim$1500~K. We also find that a partially transparent aerosol component is frequently present and that it is typically vertically distributed throughout the atmospheric column. Our findings also suggest that while clouds and hazes are common in exoplanet atmospheres, the majority of planets have some level of detectable spectral modulation. Additionally, the empirical trend that clouds and hazes are minimized at 1460.86K$^{+316}_{-405}$ revealed in our catalog has predictive utility for modelling the performance of large-scale transiting exoplanets survey, such as planned with the Ariel mission. This trend can also be used for making a probability-based forecast of spectral modulation for a given source in the context of future JWST observations. Future observations including the optical and/or a broader spectral coverage may be useful to further quantify the trend reported here.
