Revisiting K2-233 spectroscopic time-series with multidimensional Gaussian processes
Revisiting K2-233 spectroscopic time-series with multidimensional Gaussian processes
复制标题
使用多维高斯过程重新审视 K2-233 光谱时间序列
DOI：
10.1093/mnras/stad1139
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发表时间：
2023
影响因子：
4.8
通讯作者：
Barragán O
中科院分区：
文献类型：
--
作者：
Barragán O
探测年轻恒星径向速度时间序列中的行星特征是具有挑战性的，因为它们固有的强烈恒星活动。然而，通过使用从用于提取径向速度的相同恒星光谱测量的活动指标，可以了解关于恒星信号的属性的信息。在这份手稿中，我们提出了一个光谱的高精度径向速度行星搜索器数据的年轻星星K2-233，它拥有三个凌日行星的重新分析。我们进行多维高斯过程回归的径向速度和活动指标来表征行星多普勒信号。我们证明，第一次在一个真实的数据集，使用一个多维高斯过程可以提高精度，我们测量的行星信号相比，一个一维的高斯过程应用到径向速度。我们测量K2-233 B、c和d的半振幅为、、和，分别转化为行星质量、和M。这些新的质量测量使K2-233 d成为JWST透射光谱观测的有价值的目标。K2-233是唯一一个在半径谷以下发现两颗内行星，在半径谷以上发现第三颗外行星的年轻系统。这使得它成为进行比较研究的绝佳目标，为我们的行星演化，形成，迁移和大气演化理论提供信息。
Detecting planetary signatures in radial velocity time-series of young stars is challenging due to their inherently strong stellar activity. However, it is possible to learn information about the properties of the stellar signal by using activity indicators measured from the same stellar spectra used to extract radial velocities. In this manuscript, we present a reanalysis of spectroscopic High Accuracy Radial Velocity Planet Searcher data of the young star K2-233, which hosts three transiting planets. We perform a multidimensional Gaussian process regression on the radial velocity and the activity indicators to characterize the planetary Doppler signals. We demonstrate, for the first time on a real data set, that the use of a multidimensional Gaussian process can boost the precision with which we measure the planetary signals compared to a one-dimensional Gaussian process applied to the radial velocities alone. We measure the semi-amplitudes of K2-233 b, c, and d as,, and, which translate into planetary masses of,, andM⊕, respectively. These new mass measurements make K2-233 d a valuable target for transmission spectroscopy observations withJWST. K2-233 is the only young system with two detected inner planets below the radius valley and a third outer planet above it. This makes it an excellent target to perform comparative studies, to inform our theories of planet evolution, formation, migration, and atmospheric evolution.