论文标题
使用低s/n传输时间变化的50多个开普勒行星的质量上限
Mass Upper Bounds for Over 50 Kepler Planets Using Low-S/N Transit Timing Variations
论文作者
论文摘要
扩展开普勒样本可用质量测量值的前景有限。通常，行星质量是通过多台面系统中的宿主星恒星的径向速度（RV）测量来推断的。但是，大多数开普勒主机对RV随访太暗了，并且只有一定数量的系统具有足够强的TTV用于时间序列建模。在这里，我们使用低信噪比（S/N）TTV开发了一种在多平板系统中限制行星质量的方法。对于来自加利福尼亚州捕捞者调查的79个多台网系统中的175个行星的样本，我们使用开普勒公开可用的TTV时间序列推断了行星质量的后代。对于53个行星（我们样本的$> 30 \％$），低s/n TTV会在行星质量上产生信息丰富的上限，即质量约束与先前的质量差异很大，并产生物理上合理的体积组成。对于25个小行星，低s/n TTV有利于挥发性丰富的成分。在可用的情况下，基于低S/N TTV的低质量约束与RV衍生的质量一致。 TTV时间序列可公开用于每个开普勒星球，开普勒系统的紧凑性使基于TTV的约束对于大量多层网系统提供了信息。利用Low-S/N TTVS为增加开普勒样本的可用质量限制提供了宝贵的途径。
Prospects for expanding the available mass measurements of the Kepler sample are limited. Planet masses have typically been inferred via radial velocity (RV) measurements of the host star or time-series modeling of transit timing variations (TTVs) in multiplanet systems; however, the majority of Kepler hosts are too dim for RV follow-up, and only a select number of systems have strong enough TTVs for time-series modeling. Here, we develop a method of constraining planet mass in multiplanet systems using low signal-to-noise ratio (S/N) TTVs. For a sample of 175 planets in 79 multiplanet systems from the California-Kepler Survey, we infer posteriors on planet mass using publicly available TTV time-series from Kepler. For 53 planets ($>30\%$ of our sample), low-S/N TTVs yield informative upper bounds on planet mass, i.e., the mass constraint strongly deviates from the prior on mass and yields a physically reasonable bulk composition. For 25 small planets, low-S/N TTVs favor volatile-rich compositions. Where available, low-S/N TTV-based mass constraints are consistent with RV-derived masses. TTV time-series are publicly available for each Kepler planet, and the compactness of Kepler systems makes TTV-based constraints informative for a substantial fraction of multiplanet systems. Leveraging low-S/N TTVs offers a valuable path toward increasing the available mass constraints of the Kepler sample.
