用中分辨光谱法测量HR 8799 b和c的径向速度
Radial Velocity Measurements of HR 8799 b and c with Medium Resolution Spectroscopy
摘要：
高对比度介质分辨率光谱学已被用于检测气体巨行星大气中的水和一氧化碳等分子。在这项工作中，我们展示了如何可以用来获得径向速度（RV）直接成像的系外行星的测量。改进传统的互相关技术，我们开发了一种新的可能性，基于行星信号和星光背景的联合前向建模（即，斑点）。在对星光模型进行边缘化之后，我们推断HR 8799 b和c在2010年的重心RV分别为-9.2 +-0.5 km/s和-11.6 +-0.5 km/s。这些RV测量有助于通过解决升交点经度的简并来约束行星轨道的3D方向。假设HR 8799 b和c的轨道共面，但不包括d和e，我们估计Ω= 89（+27，-17）deg和i = 20.8（4.5，-3.7）deg。
英文摘要：
High-contrast medium resolution spectroscopy has been used to detect molecules such as water and carbon monoxide in the atmospheres of gas giant exoplanets. In this work, we show how it can be used to derive radial velocity (RV) measurements of directly imaged exoplanets. Improving upon the traditional cross-correlation technique, we develop a new likelihood based on joint forward modelling of the planetary signal and the starlight background (i.e., speckles). After marginalizing over the starlight model, we infer the barycentric RV of HR 8799 b and c in 2010 yielding -9.2 +- 0.5 km/s and -11.6 +- 0.5 km/s respectively. These RV measurements help to constrain the 3D orientation of the orbit of the planet by resolving the degeneracy in the longitude of ascending node. Assuming coplanar orbits for HR 8799 b and c, but not including d and e, we estimate Ω= 89 (+27,-17) deg and i = 20.8 (4.5,-3.7) deg.
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。
