发表机构
Kapteyn Astronomical Institute, University of Groningen; Waterloo Centre for Astrophysics and Department of Physics and Astronomy, University of Waterloo; School of Physics and Astronomy, University of Birmingham; Center for Star and Planet Formation, Globe Institute, University of Copenhagen; Space Telescope Science Institute; Department of Physics, University of Warwick; Department of Physics and Astronomy, York University; Trottier Space Institute, McGill University（格罗宁根大学卡普坦天文研究所; 滑铁卢大学天体物理中心及物理与天文学系; 伯明翰大学物理与天文学院; 哥本哈根大学全球研究所恒星与行星形成中心; 太空望远镜科学研究所; 华威大学物理系; 约克大学物理与天文学系; 麦吉尔大学特罗蒂尔空间研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用 PROTEUS 框架预测五颗超短周期岩石行星的热演化，发现多数倾向裸岩状态，并揭示大气存活所需的逃逸效率阈值，为 JWST 观测提供指导。
AI 中文摘要
超短周期（USP）岩石系外行星的昼侧温度可能高到足以维持永久岩浆洋，它们处于内部地球物理学与大气化学的交叉点。熔融表面与脱气大气之间的耦合反馈可以维持或增强挥发性包层，而恒星相互作用则可能侵蚀它。理解哪种结果占主导，及其可观测印记，需要针对处于热演化不同阶段的行星采取多目标方法。我们给出了 JWST 第 4 周期项目 8864 的五个目标（TOI-1807 b、TOI-2260 b、TOI-431 b、TOI-6255 b 和 TOI-2431 b）的预测。利用 PROTEUS 耦合内部-大气框架，我们构建了一个模拟网格，并将结果分为六类，由最终内部熔融状态以及行星是否保留足够厚、足以将热量重新分配至夜侧的可探测大气来定义。对于保留不可忽略挥发性包层的目标，我们的模型预测，当表面熔融时，大多数物种的分压更高，但 S$_{2}$ 除外，其在固态状态下的增强表明它可能作为内部熔融状态的示踪剂。尽管一些目标在多种情景下显示出结果，但大多数倾向于裸岩端元，全球熔融分数 $\leq$ 20%，且大气保留对逃逸效率敏感。我们的分析揭示了在能量限制逃逸下挥发性包层得以存续的最低逃逸效率阈值，从而约束了受辐照岩石行星上大气存活所需的条件。这些预测将指导 MIRI-LRS 相位曲线观测的解释，并识别哪些目标和特征最能区分相互竞争的地球物理状态。
英文摘要
Ultra-short-period (USP) rocky exoplanets can have dayside temperatures high enough to maintain permanent magma oceans, sitting at the intersection of interior geophysics and atmospheric chemistry. Coupled feedbacks between the molten surface and outgassed atmosphere can sustain or enhance a volatile envelope, while stellar interactions can erode it. Understanding which outcome prevails, and its observable imprint, requires a multi-target approach across planets at different stages of thermal evolution. We present predictions for the five targets of JWST Cycle 4 program 8864: TOI-1807 b, TOI-2260 b, TOI-431 b, TOI-6255 b, and TOI-2431 b. Using the PROTEUS coupled interior-atmosphere framework, we construct a simulation grid and classify outcomes into six categories, defined by the final interior melt state and by whether the planet retains a detectable atmosphere thick enough to redistribute heat to the nightside. For targets retaining a non-negligible volatile envelope, our models predict higher partial pressures for most species when the surface is molten, except for S$_{2}$, whose enhancement in the solid regime suggests it may serve as a tracer of interior melt state. Despite some targets showing outcomes across multiple scenarios, most tend toward a bare-rock end-member, with global melt fraction $\leq$ 20\% and atmospheric retention sensitive to escape efficiency. Our analysis reveals a minimum escape efficiency threshold below which volatile envelopes survive under energy-limited escape, constraining the conditions required for atmosphere survival on irradiated rocky planets. These predictions will guide interpretation of MIRI-LRS phase curve observations and identify which targets and features best discriminate between competing geophysical states.
CommentsSubmitted to ApJ, comments are welcome
