X-raying the local interstellar medium

星际介质(ISM)，即恒星之间的气体和尘埃，调节着恒星的生命周期和银河系的动力学。ISM可以通过多种观测技术进行研究，包括21厘米射电发射、IR和UV。特别是X射线光谱学，构成了研究ISM的有力方法，因为X射线光子不仅与原子气体相互作用，而且与分子和固体(即尘埃)相互作用。因此，通过X射线天文观测，我们可以研究ISM的物理性质和化学成分。我们建议通过模拟银河源的X射线吸收光谱特征来表征ISM中氢原子和分子的空间分布。通过对XMM-牛顿X射线天文台获得的银河源X射线光谱进行拟合，结合GAIA天文台测量的距离，我们将创建前所未有的ISM密度分布的3D地图，如X射线能带上所见。

The interstellar medium (ISM), gas and dust between the stars, regulates the star life cycles and the dynamics of the Galaxy. The ISM can be studied by multiple observational techniques, including 21 cm radio emission, IR, and UV. X-ray spectroscopy, in particular, constitute a powerful method to study the ISM because X-ray photons interacts not only with the atomic gas but also with molecules and solid (i.e. dust). Hence, by using X-ray astronomical observations, we can study the ISM physical properties and chemical composition. We propose to characterize the spatial distribution of the hydrogen atoms and molecules in the ISM by modeling X-ray absorption spectral features of Galactic sources. By fitting X-ray spectra of Galactic sources, obtained with the XMM-Newton X-ray observatory, in combination with distances measured with the GAIA observatory, we will create unprecedented 3D map of the ISM density distribution, as seen on the X-ray energy band.