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arXiv 2301.04062astro-ph.EP
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开普勒短节奏观测揭示的一个深半径谷

A deep radius valley revealed by Kepler short cadence observations

Cynthia S. K. Ho, Vincent Van Eylen

备注：
19 pages, 17 figures, accepted in MNRAS
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摘要：

半径谷的特征，即，观测到的1.5-2地球半径之间的行星周期短于约100天，为近距离行星的形成和演化提供了见解。我们通过使用开普勒1分钟短节奏观测重新调整431颗行星的凌日，呈现了半径谷的新视图，其中绝大多数以前从未以这种方式进行过分析。在某些情况下，更新的行星参数与以前的研究有很大不同，导致半径谷比以前观察到的更深。这表明行星在形成时可能具有更均匀的核心成分。此外，使用支持向量机，我们发现，半径谷的位置强烈依赖于轨道周期和恒星质量和弱依赖于恒星年龄，与$\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{P} = -0.096_{-0.027}^{+0.023}$，$\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{M_{\star}} = 0.231_{-0.064}^{+0.053}$，和$\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{\left( \text{age} \right)} = 0.033_{-0.025}^{+0.017}$。这些研究结果有利于热驱动的质量损失模型，如光蒸发和核心供电的质量损失，与后一种情况略有偏好。最后，这项工作突出了短测光节奏的过境观测的价值，以精确地确定行星半径，我们提供了一个更新的列表，精确和均匀确定的参数，为我们的样本中的行星。

英文摘要：

The characteristics of the radius valley, i.e., an observed lack of planets between 1.5-2 Earth radii at periods shorter than about 100 days, provide insights into the formation and evolution of close-in planets. We present a novel view of the radius valley by refitting the transits of 431 planets using Kepler 1-minute short cadence observations, the vast majority of which have not been previously analysed in this way. In some cases, the updated planetary parameters differ significantly from previous studies, resulting in a deeper radius valley than previously observed. This suggests that planets are likely to have a more homogeneous core composition at formation. Furthermore, using support-vector machines, we find that the radius valley location strongly depends on orbital period and stellar mass and weakly depends on stellar age, with $\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{P} = -0.096_{-0.027}^{+0.023}$, $\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{M_{\star}} = 0.231_{-0.064}^{+0.053}$, and $\partial \log {\left(R_{p, \text{valley}} \right)}/ \partial \log{\left( \text{age} \right)} = 0.033_{-0.025}^{+0.017}$. These findings favour thermally-driven mass loss models such as photoevaporation and core-powered mass loss, with a slight preference for the latter scenario. Finally, this work highlights the value of transit observations with short photometric cadence to precisely determine planet radii, and we provide an updated list of precisely and homogeneously determined parameters for the planets in our sample.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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