The outer atmospheres of cool M dwarfs

众所周知，M矮星表现出截然不同的磁性活动水平，表现在恒星黑子、x射线发射和（在光波波段）色球发射线上。为了更好地了解M矮星不同光谱亚类型和活动水平下这些被加热的外层大气的物理特性，我们建议在该资助申请的框架内对这些恒星进行1D和3D色球建模。我们特别建议计算三维色球模型和一维色球模型，并检查大气不均匀性是否可以通过一维模型的单一或线性组合来解释，并将这种建模与CARMENES获得的最新观测结果并列。因此，我们建议使用大气代码PHOENIX来构建M矮星的经典1D色球模型网格，并将我们的建模与CARMENES光谱仪的高分辨率光谱观测相结合。对于选定的天体，我们建议在观测光谱和模型光谱之间进行详细的比较，以更好地表征选定的单个恒星的色球的物理特性。

M dwarfs are known to exhibit vastly different levels of magnetic activity, manifesting itself in star spots, X-ray emission and - at optical wavebands - chromospheric emission lines. In order to better understand the physics of these heated outer atmospheric layers for different spectral sub-types and activity levels among M dwarfs, we propose to perform 1D and 3D chromospheric modeling for these stars in the framework of this funding application. We specifically propose to compute both 3D chromospheric models and 1D chromospheric models and check, if the atmospheric inhomogeneities can be accounted for by single or linear combinations of 1D models, and juxtapose this modeling with state-of-the-art observations obtained by CARMENES. We therefore propose to use the atmosphere code PHOENIX for constructing a model grid of classical 1D chromospheres for M dwarfs and confront our modeling with high-resolution spectral observations taken with the CARMENES spectrograph. For selected objects we propose to perform a detailed comparison between observed and modeled spectra to better characterize the physics of the chromospheres of the selected individual stars.