期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 510, 期 1, 页码 620-629出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stab3432
关键词
radiative transfer; methods: numerical; planets and satellites: atmospheres
资金
- Wolfson Harrison UK Research Council Physics Scholarship
- Science and Technology Facilities Council (STFC)
Transmission spectra of transiting exoplanets provide valuable information about their atmospheres. In this study, a new formula is derived to estimate the opening angle of a planet, which determines the atmospheric region impacting the transmission spectrum. Results show that the opening angle varies among different types of planets, with ultra-hot Jupiters having a smaller opening angle compared to other planets.
Transmission spectra contain a wealth of information about the atmospheres of transiting exoplanets. However, large thermal and chemical gradients along the line of sight can lead to biased inferences in atmospheric retrievals. In order to determine how far from the limb plane the atmosphere still impacts the transmission spectrum, we derive a new formula to estimate the opening angle of a planet. This is the angle subtended by the atmospheric region that contributes to the observation along the line of sight, as seen from the planet centre. We benchmark our formula with a 3D Monte Carlo radiative transfer code and we define an opening angle suitable for the interpretation of JWST observations, assuming a 10-ppm noise floor. We find that the opening angle is only a few degrees for planets cooler than ca. 500 Kelvins, while it can be as large as 25 degrees for (ultra-)hot Jupiters and 50 degrees for hot Neptunes. Compared to previous works, our more robust approach leads to smaller estimates for the opening angle across a wide range scale heights and planetary radii. Finally, we show that ultra-hot Jupiters have an opening angle that is smaller than the angle over which the planet rotates during the transit. This allows for time-resolved transmission spectroscopy observations that probe independent parts of the planetary limb during the first and second half of the transit.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据