Reproduction package for Spectroscopically resolved partial phase curve of the rapid heating and cooling of the highly-eccentric Hot Jupiter HAT-P-2b with WFC3

This is a basic reproduction package for the paper "Spectroscopically resolved partial phase curve of the rapid heating and cooling of the highly-eccentric Hot Jupiter HAT-P-2b with WFC3"

by [Jacobs, B.; Désert, J. -M.; Lewis, N. et al. (2024)]

Abstract:

The extreme environments of transiting close-in exoplanets in highly-eccentric orbits serve as ideal laboratories for testing exo-atmospheric physics. Spectroscopically resolved phase curves not only allow for the characterization of their thermal response to irradiation changes but also unveil phase-dependent atmospheric chemistry and dynamics.

We observed a partial phase curve of the highly-eccentric close-in giant planet HAT-P-2b (e = 0.51023)with the Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope. Using these data, we update the planet’s orbital parameters and radius, and we retrieve high-frequency pulsations consistent with those reported in Spitzer data. We find that the peak in planetary flux occurs at 6.7 ± 0.6 hr after periastron, with a heating timescale of 9.0+3.5−2.1 hr, and a cooling timescale of 3.6+0.7−0.6 hr. We compare the light-curve to a suite of1-dimensional and 3-dimensional forward models, varying the planet’s chemical composition. The strong contrast in flux increase and decrease timescales before and after periapse indicates an opacity term that emerges during the planet’s heating phase. We suggest that more emerging H− than expected from chemical equilibrium models could be the reason for the mismatch between models and the data.

We used a common-mode based method that does not assume a functional form to extract phase-resolved spectra. The analysis of these spectra is challenging because of the unknown accuracy of the spectral slope and absolute flux levels. The phase-resolved spectra are largely featureless, possibly indicating an inhomogeneous dayside. However, we identified an anomalously high flux in the spectroscopic bin that coincides with the hydrogen Paschen β line and that is potentially connected to the planet’s orbit. We exclude an instrumental origin and we discuss several alternative, astrophysical origins.

本资源为论文《利用宽视场相机3（Wide Field Camera 3, WFC3）观测高偏心率热木星（Hot Jupiter）HAT-P-2b的快速升温和降温的光谱分辨部分相位曲线》的基础复现套件，作者为Jacobs, B.; Désert, J.-M.; Lewis, N. 等（2024）。

摘要：
处于高偏心率轨道的近距离凌日系外行星拥有极端环境，是检验系外大气物理的理想实验室。光谱分辨的相位曲线不仅可用于表征行星对辐照变化的热响应特征，还能揭示相位依赖的大气化学与动力学过程。

研究团队借助哈勃空间望远镜搭载的宽视场相机3（Wide Field Camera 3, WFC3），对高偏心率热木星（Hot Jupiter）HAT-P-2b（偏心率e=0.51023）的部分相位曲线开展观测。基于这批观测数据，我们更新了该行星的轨道参数与半径，并检索到与斯皮策（Spitzer）数据中报道一致的高频脉动信号。研究发现，行星流量峰值出现在近星点后6.7±0.6小时，对应的升温时标为9.0+3.5−2.1小时，降温时标为3.6+0.7−0.6小时。我们将该光变曲线与一系列一维、三维正向模型进行对比，模型中行星的化学组成各不相同。近星点前后流量增减时标的显著差异表明，行星升温阶段存在一种新的不透明度来源。我们推测，相较于化学平衡模型的预测，更多的H−离子生成可能是导致模型与观测数据不匹配的原因。

我们采用了一种不假设函数形式的共模方法来提取相位分辨光谱。由于光谱斜率与绝对流量水平的精度未知，对这批光谱的分析颇具挑战。相位分辨光谱整体特征较为平淡，这可能意味着行星昼侧存在非均匀性。不过，我们在与氢帕邢β（Paschen β）谱线重合的光谱波段中发现了异常偏高的流量信号，该信号或与行星轨道存在关联。我们排除了仪器起源的可能性，并对多种可能的天体物理起源进行了讨论。