Thermo-chemical Evolution and Formation of Super-Earths and Mini-Neptunes

自从我们有证据证明行星在其他恒星的轨道上运行以来，只有25年。在这短短的一段时间内，系外行星的这一新的研究领域已经从研究大型气态物体过渡到现在强烈关注低质量系外行星：超级地球和迷你海王星。由于不在我们的太阳系中，我们无法预测它们的存在。然而，我们有证据表明，这样的行星是银河系中最常见的天体，很明显，它们为几乎完全未被探索的物理机制提供了丰富的见解。它们是当前和即将到来的密集观测活动的有价值的主题，这意味着了解这些行星的物理学的竞赛正在进行。由于超级地球和迷你海王星主要是岩石，尽管后者有一个小而重要的气体大气层，仅用天文学的理论方法来研究这些行星是不够的。复杂的岩石内部决定了它们的物理特性，最好用地球物理原理来描述。这正是我解决问题的独特方法，结合天体物理学和天体物理学，这是我与大多数研究行星的天文学家不同的地方。我的跨学科方法让我深入研究那些在其他方面解决不好的基础问题，并巩固了我在超级地球和迷你海王星研究中的领导地位。为此，在本提案中，我为我的研究团队描述了一个调查计划，其目标是：（1）了解自然界产生的低质量系外行星的行星组成范围，（2）确定巨型撞击碰撞在塑造低质量行星群组成方面的作用，（3）绘制大气成分与岩石和海洋超级地球内部动力学之间的联系，以便将观测与内部物理过程联系起来，（4）确定是什么决定了行星中的挥发物含量，（5）了解潮汐加热如何影响可居住性。这项国际领先的研究将对天文学和行星科学界产生巨大影响，并将巩固加拿大在系外行星领域的领导地位。这一研究领域正在呈指数级增长，并有望产生令人惊叹的结果，同时与不同的受众高度相关。这里提出的关于超级地球和迷你海王星的创新研究，加上“加拿大制造”的印章，将吸引新的人才加入加拿大的STEM方案，并吸引公众的注意力。

It has been only 25 years since we have had evidence for planets in orbit around other stars. Over this short period of time, this new research field of exoplanets has transitioned from studying the large gaseous objects, to now focusing intensely on the low-mass exoplanets: super-Earths and mini-Neptunes. Absent from our solar system, we had not predicted their existence. However, we have evidence that such planets are the most common astrophysical objects in the Galaxy, and it is clear that they provide rich insight into an almost totally unexplored physical regime. They are the worthy subjects of current and upcoming intense observational campaigns, which means the race is on to understand the physics of these planets. Because super-Earths and mini-Neptunes are predominantly rocky, albeit the latter having a small and important gaseous atmosphere, an astronomy-only theoretical approach to studying these planets is inadequate. The complex rocky interior dominates their physical properties and is best described using geophysical principles. This is precisely the distinctive approach I bring to problem-solving, combining astrophysics and geophysics, and it is what sets me apart from most astronomers studying planets. My interdisciplinary approach lets me dive into foundational questions that are otherwise poorly solved and underpins my leadership in the study of super-Earths and mini-Neptunes. To this end, in this proposal I describe a program of investigation for my research team whose goals are to: (1) understand the range of planetary compositions that nature produces for low-mass exoplanets, (2) determine the role of giant impact collisions in shaping the composition of the low-mass planet population, (3) map the connections between atmospheric composition and interior dynamics of rocky and ocean super-Earths in order to connect observations to interior physical processes, (4) determine what sets the volatile content in a planet, and (5) understand how tidal heating affects habitability. This internationally-leading research will have tremendous impact on the astronomy and planetary science communities and will consolidate Canada's leadership in the area of exoplanets. This research field is exponentially growing and poised to produce wondrous results, while being highly-relatable to a diverse audience. The innovative research proposed here on super-Earths and mini-Neptunes, with the `made-in-Canada' seal, will attract new talent to Canadian STEM programs and captivate the public's attention.