The formation and detectability of exomoons

太阳系中所有较大的行星都有天然卫星。特别是冰和气体巨行星拥有200多颗卫星，甚至像矮行星这样质量较小的物体也有伴星环绕。从太阳系可以推断出卫星是太阳系外行星周围的常见物体。讨论了几种形成通道：捕获形成的卫星，巨大撞击形成的卫星，以及在环绕行星的圆盘上聚集形成的系外卫星。到目前为止，已经发现了2600多个系外行星系统，其中包含4000多颗行星。观测表明，最丰富的行星是轨道周期短于100天的超级地球（质量为地球1-20倍的行星），其次是距离中心恒星1-3个天文单位的巨行星。然而，直到今天，还没有确认检测到系外卫星，这主要是由于当前一代望远镜的灵敏度几乎足以探测到大质量系外行星周围的大质量系外卫星。在手头的这个提案中，我们打算研究由巨大的冰和气体巨星撞击形成的系外卫星。

All larger planets in the Solar System have natural satellites. Especially the ice and gas giants harbour together over 200 moons, and even less massive objects like dwarf planets are orbited by companions. From the Solar System one might deduce that moons are common objects in extrasolar systems around exoplanets. Several formation channels are diskussed: the formation of moons by capture, the formation by giant impacts, and the formation of exomoons by agglomeration in a circumplanetary disk. Up to the present, over 2600 exoplanetary systems that contain over 4000 planets have been diskovered.The observations show that the most abundant planets are super-Earths (planets with 1-20 Earth masses) with orbital periods shorter than 100 days, followed by giant planets at distances of 1-3 astronomical units from their central star. However, there is no confirmed detection of an exomoon until the present day, mostly due to the current generation telescope sensitivity which is almost sufficient to detect massive exomoons around massive exoplanets. In this proposal at hand, we intend to study the formation of exomoons by giant impacts on ice and gas giants.