Linking exoplanet detection to formation: population synthesis

几个世纪以来，行星围绕其他恒星运行的可能性一直是一个令人着迷的话题。我们是第一代把这些行星——现在被称为系外行星——从科幻小说领域带入科学领域的人。一个重要的里程碑是发现了几颗围绕脉冲星运行的行星（Wolszczan &体弱，1992），其次是第一颗围绕与太阳更相似的恒星运行的行星（Mayor & Queloz, 1995），这一成就获得了2019年诺贝尔物理学奖。自那以后的25年里，我们有了大量令人兴奋的发现，今天我们知道了4000多颗系外行星。这些行星表现出令人难以置信的多样性。为什么这么多行星的轨道都很小——通常比水星的轨道小得多？是什么导致行星变成岩石、气体或介于两者之间？为什么有些行星的轨道是强烈偏心的，或者与它们的主恒星的旋转不一致？当恒星远离主序星时，行星会发生什么？哪些行星是研究其大气层最有利和最有趣的目标？我们的太阳系有多独特——我们是唯一的吗？系外行星科学是一个年轻的研究领域，有许多突破性的新发现的巨大潜力。在这个博士项目中，我们将寻求将数千颗系外行星的发现与行星形成模型联系起来，即所谓的人口合成模型。在接下来的几年里，已知的系外行星的数量预计将增加一倍甚至三倍，这得益于互补观测技术的进步，如凌日测量、径向速度观测、系外行星直接成像、微透镜数据和即将到来的天体测量行星探测。在这个博士项目中，我们将尝试将模拟的行星人口综合模型与观测到的行星结构、人口统计和主星属性的图片联系起来，以测试行星形成的潜在物理原理。

The possibility of planets orbiting other stars has been a topic of fascination for centuries. We are the first generation that has brought these planets - now known as exoplanets - from the realm of science-fiction into that of science. An important milestone was the discovery of several planets orbiting a pulsar (Wolszczan & Frail, 1992), followed by the first planet orbiting a star more similar to our Sun (Mayor & Queloz, 1995), an achievement awarded the 2019 Nobel Prize in Physics. The 25 years since have been filled with an abundance of exciting discoveries and today we know over 4000 exoplanets. These planets exhibit an incredible diversity of properties. Why do so many planets have tiny orbits - often much smaller than that of Mercury? What causes planets to become rocky, gaseous, or something in between? Why do some planets have orbits that are strongly eccentric, or misaligned with the rotation of their host stars? What happens to planets when stars evolve away from the main sequence? Which planets are the most favourable and interesting targets for studies of their atmospheres? How unique is our solar system - are we alone? Exoplanet science is a young field of research and there is great potential for many ground-breaking new discoveries. During this PhD project we will seek to link the discovery of thousands of exoplanets to planet formation models, in what is known as population synthesis modelling. Over the next years, the number of known exoplanets is expected to double or even triple, powered by progress in complementary observing techniques such as transit measurements, radial velocity observations, directly imaged exoplanets, microlensing data, and forthcoming astrometric planet detections. During this PhD project, we will attempt to link simulated planet population synthesis models to the observed picture of planet architecture, demographics, and host star properties, to test the underlying physics of planet formation.