HIGH RESOLUTION TRANSMISSION SPECTROSCOPY AS A DIAGNOSTIC FOR JOVIAN EXOPLANET ATMOSPHERES: CONSTRAINTS FROM THEORETICAL MODELS
HIGH RESOLUTION TRANSMISSION SPECTROSCOPY AS A DIAGNOSTIC FOR JOVIAN EXOPLANET ATMOSPHERES: CONSTRAINTS FROM THEORETICAL MODELS
复制标题
高分辨率透射光谱诊断木星系外行星大气：理论模型的限制
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
K. Heng
中科院分区：
文献类型：
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作者：
E. Kempton;R. Perna;K. Heng
我们从一个耦合的三维（3D）大气动力学和透射光谱模型中提出了高分辨率的巨行星大气透射光谱，该模型包括由风和行星运动引起的多普勒频移。我们模拟的类木行星的入射通量超过两个数量级，对应于绕太阳型恒星运行0.9-55天轨道周期的行星。我们的三维动力学模型的结果揭示了在简单的一维（1D）模型中不存在的高分辨率透射光谱的某些方面。我们发现最热的行星经历强烈的亚恒星到反恒星（SSAS）风，导致透射光谱的净蓝移高达3 km s - 1，而较少辐照的行星几乎没有净多普勒频移。我们发现有逆温的大气和没有逆温的大气的透射光谱只有很小的差别。与1D模式相比，由于旋转（在潮汐锁定的假设下，近地行星的速度更快）和大气风的联合作用，在最热的大气中，由于多普勒展宽，峰值谱线强度显著降低。最后，高分辨率透射光谱可能有助于研究具有光学厚云的系外行星的大气，因为非常强跃迁的线核应该在非常高的高度保持光学厚。高分辨率透射光谱是对三维大气动力学模型有效性的一个很好的观测测试，因为它们提供了对风结构和热循环的直接探测。基于地面的系外行星光谱学目前即将能够验证我们的一些建模预测，最值得注意的是SSAS风对日照的依赖。我们提醒说，基于一维大气模型的高分辨率透射光谱解释可能是不够的，因为三维大气运动可以对吸收特征产生明显的影响。
We present high resolution transmission spectra of giant planet atmospheres from a coupled three-dimensional (3D) atmospheric dynamics and transmission spectrum model that includes Doppler shifts which arise from winds and planetary motion. We model Jovian planets covering more than two orders of magnitude in incident flux, corresponding to planets with 0.9–55 day orbital periods around solar-type stars. The results of our 3D dynamical models reveal certain aspects of high resolution transmission spectra that are not present in simple one-dimensional (1D) models. We find that the hottest planets experience strong substellar to anti-stellar (SSAS) winds, resulting in transmission spectra with net blueshifts of up to 3 km s−1, whereas less irradiated planets show almost no net Doppler shifts. We find only minor differences between transmission spectra for atmospheres with temperature inversions and those without. Compared to 1D models, peak line strengths are significantly reduced for the hottest atmospheres owing to Doppler broadening from a combination of rotation (which is faster for close-in planets under the assumption of tidal locking) and atmospheric winds. Finally, high resolution transmission spectra may be useful in studying the atmospheres of exoplanets with optically thick clouds since line cores for very strong transitions should remain optically thick to very high altitude. High resolution transmission spectra are an excellent observational test for the validity of 3D atmospheric dynamics models, because they provide a direct probe of wind structures and heat circulation. Ground-based exoplanet spectroscopy is currently on the verge of being able to verify some of our modeling predictions, most notably the dependence of SSAS winds on insolation. We caution that interpretation of high resolution transmission spectra based on 1D atmospheric models may be inadequate, as 3D atmospheric motions can produce a noticeable effect on the absorption signatures.
热行星大气流动模拟中的弛豫时间和耗散相互作用
DOI：
10.1088/0004-637x/729/2/117
发表时间：
2011
期刊：
The Astrophysical Journal
影响因子：
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作者：
Thrastarson H
通讯作者：
Thrastarson H