论文标题
saturn kelt-11b的不寻常的传播光谱，暗示了亚磨性水丰度
An Unusual Transmission Spectrum for the Sub-Saturn KELT-11b Suggestive of a Sub-Solar Water Abundance
论文作者
论文摘要
我们提出了用过渡的外部外行星调查卫星（TESS），Hubble太空望远镜（HST）田间摄像头3 G141光谱镜头镜头（HUBBLE SPACE CAMPOPE（HST）光谱光谱Grism和Spitzer Spitzer Space望远镜（Spitzer）在3.6 $ $ M M，MM M M，MM M M，MM M M M，MM M M，，我们提出了用过境外行星调查卫星（TESS），Hubble Space望远镜（HST）的田野相机3 G141光谱相机3 G141光谱摄像头（HUBBLE太空望远镜（HST）$ M M，日食。精确的HST传输光谱显着揭示了具有异常形状的低振幅水特征。基于分子丰度变化的自由检索分析，我们发现吸收吸水的有力证据。根据模型假设，我们还找到了其他吸收剂（HCN，TIO和ALO）的初步证据。检索到的水丰度通常为$ \ Lessim 0.1 \ times $太阳能（0.001--0.7 $ \ times $ $太阳能在一系列模型假设上），基于太阳能系统金属性趋势的行星形成模型的预期低几个数量级。我们还考虑化学平衡和自洽的1D辐射感染平衡模型，发现它们也更喜欢低金属度（$ [m/h] \ Lesssim -2 $ -2 $，与免费检索结果一致）。但是，所有检索都应谨慎解释，因为它们要么需要远离化学平衡的其他吸收器来解释频谱的形状，要么仅仅适合数据。最后，我们发现Spitzer的次要日食表明从Kelt-11b的日子到夜间，假设有晴朗的日子。面对越来越精确的外部光谱测量，Kelt-11b组成的这些潜在不寻常的结果暗示了大气和地层模型的新挑战。
We present an optical-to-infrared transmission spectrum of the inflated sub-Saturn KELT-11b measured with the Transiting Exoplanet Survey Satellite (TESS), the Hubble Space Telescope (HST) Wide Field Camera 3 G141 spectroscopic grism, and the Spitzer Space Telescope (Spitzer) at 3.6 $μ$m, in addition to a Spitzer 4.5 $μ$m secondary eclipse. The precise HST transmission spectrum notably reveals a low-amplitude water feature with an unusual shape. Based on free retrieval analyses with varying molecular abundances, we find strong evidence for water absorption. Depending on model assumptions, we also find tentative evidence for other absorbers (HCN, TiO, and AlO). The retrieved water abundance is generally $\lesssim 0.1\times$ solar (0.001--0.7$\times$ solar over a range of model assumptions), several orders of magnitude lower than expected from planet formation models based on the solar system metallicity trend. We also consider chemical equilibrium and self-consistent 1D radiative-convective equilibrium model fits and find they too prefer low metallicities ($[M/H] \lesssim -2$, consistent with the free retrieval results). However, all the retrievals should be interpreted with some caution since they either require additional absorbers that are far out of chemical equilibrium to explain the shape of the spectrum or are simply poor fits to the data. Finally, we find the Spitzer secondary eclipse is indicative of full heat redistribution from KELT-11b's dayside to nightside, assuming a clear dayside. These potentially unusual results for KELT-11b's composition are suggestive of new challenges on the horizon for atmosphere and formation models in the face of increasingly precise measurements of exoplanet spectra.
