论文标题
部分可观测时空混沌系统的无模型预测
Revisiting Radial Velocity Measurements of the K2-18 System with the Line-by-Line Framework
论文作者
论文摘要
多年来，互相关函数和模板匹配技术已经统治了精确径向速度的世界。最近，一种名为“逐线”的新技术已被开发为一种离群的抗性方法，可有效从高分辨率光谱中提取径向速度含量。我们将这种新方法应用于K2-18系统的归档竖琴和carmenes数据集。在使用逐线框架重新处理HARPS数据集后，我们能够复制先前研究的发现。此外，通过将完整的波长范围分为子域，我们能够识别已接收卡门的数据集中径向速度的系统色素相关性。在处理后处理以消除这种相关性并拒绝一些异常夜晚之后，我们坚强地揭示了K2-18b和K2-18C的信号，与从竖琴数据集分析中发现的群众一致。然后，我们将竖琴和卡门氏速度结合起来，以完善这两个行星的参数，特别是导致修订的质量，K2-18C的周期为$ 6.99^{+0.96} _ { - 0.99} $ { - 0.99} $ M $ _ {EART} $ {EART} $和$ 9.2072 \ $ 9.2072 \ pM0.0065 $ d，相应地相差。我们的工作彻底展示了逐线技术在提取精度径向速度信息方面的力量。
The cross-correlation function and template matching techniques have dominated the world of precision radial velocities for many years. Recently, a new technique, named line-by-line, has been developed as an outlier resistant way to efficiently extract radial velocity content from high resolution spectra. We apply this new method to archival HARPS and CARMENES datasets of the K2-18 system. After reprocessing the HARPS dataset with the line-by-line framework, we are able to replicate the findings of previous studies. Furthermore, by splitting the full wavelength range into sub-domains, we were able to identify a systematic chromatic correlation of the radial velocities in the reprocessed CARMENES dataset. After post-processing the radial velocities to remove this correlation, as well as rejecting some outlier nights, we robustly uncover the signal of both K2-18b and K2-18c, with masses that agree with those found from our analysis of the HARPS dataset. We then combine both the HARPS and CARMENES velocities to refine the parameters of both planets, notably resulting in a revised mass and period for K2-18c of $6.99^{+0.96}_{-0.99}$M$_{Earth}$ and $9.2072\pm0.0065$d, respectively. Our work thoroughly demonstrates the power of the line-by-line technique for the extraction of precision radial velocity information.
