论文标题
TNG的差距程序。 xli。 KELT-9B的气候揭示了一种新的高光谱分辨率相曲线的方法
The GAPS Programme at TNG. XLI. The climate of KELT-9b revealed with a new approach to high spectral resolution phase curves
论文作者
论文摘要
[删节]我们提出了一种新的方法，可以在非常高的光谱分辨率下研究外部球星的热发射作为轨道相的函数，并将其应用于研究超热木星Kelt-9b的气候。我们结合了3晚竖琴-N和2晚的甲虫光谱，覆盖了四足动物之间的轨道相（0.25 <Phi <0.75），当地球显示其日间半球具有不同的几何形状。我们通过互相关共同添加数千个FEI线的信号，我们将其映射到可能性函数。我们通过引入一种新方法来利用我们观察值非常高的光谱分辨率来研究：（i）FEI的线深度的相位依赖性：（ii）它们的多普勒变化。我们证实了FEI发射的先前检测，并在KELT-9B的轨道性质上证明了0.5 km S-1的合并精度。通过研究FEI线的相分辨多普勒的变化，我们在地球的轨道径向速度中检测到一个异常的异常，该速度有略微偏心的轨道（E = 0.016 $ \ pm 0.003，w = 150 $^{+150 $^{+13 \ cripcy} _ { - 11} _ { - 11} _ { - 11} _ { - { - { - {-11}，〜5σ$5σ$ Prederper）。但是，我们认为可以通过几公里S-1吹中性铁气的夜风来解释这种异常。此外，我们发现FEI发射线深度是在10度（$2σ$）内的近地点周围对称的。我们表明，这些结果与超热木星行星的一般循环模型的预测在定性上兼容。非常高分辨率的光谱阶段曲线具有敏感性，可以在整个轨道中揭示线深度及其多普勒的偏移。它们与HST和JWST获得的空间相位曲线高度互补，并为已知最热的行星的气候和大气结构打开了一个新窗口。
[Abridged] We present a novel method to study the thermal emission of exoplanets as a function of orbital phase at very high spectral resolution, and apply it to investigate the climate of the ultra-hot Jupiter KELT-9b. We combine 3 nights of HARPS-N and 2 nights of CARMENES optical spectra, covering orbital phases between quadratures (0.25 < phi < 0.75), when the planet shows its day-side hemisphere with different geometries. We co-add the signal of thousands of FeI lines through cross-correlation, which we map to a likelihood function. We investigate the phase-dependence of: (i) the line depths of FeI, and (ii) their Doppler shifts, by introducing a new method that exploits the very high spectral resolution of our observations. We confirm a previous detection of FeI emission and demonstrate a combined precision of 0.5 km s-1 on the orbital properties of KELT-9b. By studying the phase-resolved Doppler shift of FeI lines, we detect an anomaly in the planet's orbital radial velocity well-fitted with a slightly eccentric orbit (e = 0.016$\pm$0.003, w = 150$^{+13\circ}_{-11},~5σ$ preference). However, we argue that such anomaly can be explained by a day-night wind of a few km s-1 blowing neutral iron gas. Additionally, we find that the FeI emission line depths are symmetric around the substellar point within 10 deg ($2σ$). We show that these results are qualitatively compatible with predictions from general circulation models for ultra-hot Jupiter planets. Very high-resolution spectroscopy phase curves have the sensitivity to reveal a phase dependence in both the line depths and their Doppler shifts throughout the orbit. They are highly complementary to space-based phase curves obtained with HST and JWST, and open a new window into the still poorly understood climate and atmospheric structure of the hottest planets known.
