The M Star Planet Population - Bridging the Gap between Observations and Theory

行星人口合成是推进我们对行星形成和演化的理解的一个非常强大的工具。原则上，它可以告诉我们形成行星所涉及的每一种潜在机制，如小行星形成或行星-圆盘相互作用，如何影响行星的最终数量。此外，它不仅有助于了解观测到的行星多样性，还可以告诉我们目前为止没有被现有仪器探测到的行星的数量。因此，将行星种群综合模拟与一整套观测相结合是像CARMENES这样的行星搜索调查的最终目标。虽然每个单独的发现都是巨大成功的，往往是尖端仪器能力和复杂的统计方法的结果，但它也往往只是又一个相同的发现。总的来说，许多行星的发现对行星形成理论具有更大的约束力。为了取得成功，行星种群综合必须将理论计算和观测的结果结合在一起。为了进行比较，关键是要考虑潜在观测样本中的选择偏差以及探测极限，即所应用的观测策略对某些行星系统的敏感性。这意味着总体合成只能应用于选择偏差和检测限度是相当众所周知的调查，并且在整个调查中是相同的。因此，卡门调查注定要进行行星人口合成，因为它是为数不多的从一开始就以统计方式描述M恒星周围的行星人口的调查之一。

Planet population synthesis is a very powerful tool in advancing our understanding of planet formation and evolution. In principle, it can tell us how each of the underlying mechanisms involved in forming planets, such as planetesimal formation or planet-disk interactions, affects the final population of planets. Additionally, it not only helps to understand the observed planet diversity, but it can also tell us about the population of planets which escape detection with current instruments so far. As such, the combination of planet population synthesis simulations with a complete set of observations is the ultimate goal of a planet search survey such as CARMENES.While each individual discovery is a great success, often the result of cutting edge instrument capabilities and elaborate statistical methods, it is also often just one more of the same. In general many planet discoveries taken together possess more constraining power on planet formation theory.In order to be successful, planet population synthesis must bring together the results of theoretical calculations and observations.For the comparison, it is critical to take selection biases in the underlying observed sample of stars as well as detection limits, i.e. the sensitivity of the applied observational strategies to certain kind of planetary systems, into account. This implies that population synthesis can only be applied to surveys for which the selection biases and detection limits are fairly well-known, and homogeneous across the survey. Thus, the CARMENES survey is predestined for planet population synthesis, since it is one of very few surveys which were designed from the very beginning with the goal of characterizing the planet population around M stars in a statistical way.