Characterization of extrasolar planets through transmission spectroscopy

在这项资助申请的框架内，我们建议在钠D谱线上对系外行星进行透射光谱分析。在低温恒星的光谱中，钠的D1和D2谱线通常是强吸收谱线。在“热木星”的主要凌日期间，行星大气中存在的任何钠都会导致额外的吸收信号。虽然最初是在太空中进行和开创的，但最近发表的一些基于地面的行星过境期间过量钠吸收的测量结果有些争议。我们建议利用HD189733b和WASP-7b上的VLT/UVES数据，对VLT/UVES数据用于钠透射光谱的可行性进行深入研究。我们建议研究各种数据提取和准备的分析方法，用各种方法评估大地线污染的影响，研究恒星活动对钠吸收可能变化的可能影响。最后，我们建议使用大气环流模型与三维辐射传输处理相结合来计算模型钠透射曲线，并将其与现有观测结果进行比较。

In the framework of this funding application we propose to perform transmission spectroscopy of extrasolar planets in the sodium D lines. The sodium D1 and D2 lines are -- normally -- strong absorption lines in the spectrum of a cool star. During the primary transit of a ``Hot Jupiter'' any sodium present in the planetary atmosphere will lead to an additional absorption signal.While originally carried out and pioneered from space, recently a number of ground-based measurements of excess sodium absorption during planetary transits have been published with somewhat controversial results. We propose use our VLT/UVES data on HD189733b and WASP-7b for a thorough investigation of the feasibility of VLT/UVES data for sodium transmission spectroscopy. We propose to study various methods of analysis for the data extraction and preparation, assess the influence of telluric line contamination with various methods and study the possible influence of stellar activity on possible changes in the sodium absorption. Finally we propose to use atmospheric circulation models coupled with a 3D-radiative transfer treatment to compute model sodium transmission curves and compare them to the available observations.