Formation and Evolution of super-Earths and sub-Neptune Planets

在过去的20年里，随着观测的改进，我们已经从发现太阳系外的第一颗行星，一颗质量为200亿美元的行星，尺寸缩小到发现超级地球行星（比地球大几个质量），甚至采取了次海王星行星的光谱与其大气成分的信息。在寻找地球类似物的过程中，我们首先发现了它的更大版本，开辟了一个新的研究领域。在我们的太阳系中没有类似物，超级地球和次海王星是一种新型的行星，具有我们需要了解的新特征。由于越来越多的发现，我们现在有足够的数据来研究控制这些物体的物理过程。 我的研究项目涉及这些行星的组成，起源和演化的基本问题。通过推断这些物体的组成，我们获得了关于形成的位置和时间的信息。我们的研究包括研究有关形成的两个方面：通过理论模型，我们的目标是了解大气蒸发如何塑造这些行星的包络，并通过建模形成的最终阶段并将其与化学成分联系起来，我们将量化固体行星的组成结果。这将使我们能够了解在其他恒星周围的行星中，类似地球和类似水星的成分是多么常见。 此外，我们知道行星会演化出适合居住的条件，而地球的热演化在使其适合生命方面发挥了作用。超级地球通常会经历与地球和其他太阳系固体行星截然不同的表面温度，热量预算和地幔成分。我们的目标是推广热演化研究和了解地幔对流的广义条件下，适合岩石/冰超级地球。为了帮助未来的观测，我们将把地幔对流与大气的放气结合起来，以追踪类地行星可居住性的途径。这项研究计划将帮助我们在广泛的行星背景下了解地球和太阳系行星。

In the last 20 years, with improvement in observations, we have gone from discovering the first planet, a Jupiter-mass planet, outside the solar system, moving down in size to discovering super-Earth planets (a few masses larger than Earth), to even taking the spectrum of a sub-Neptune planet with information on its atmospheric composition. In the quest to finding an Earth analog, we are discovering the larger versions of it first, opening a new field of study. With no analog in our Solar System, super-Earths and sub-Neptunes are a new type of planet with novel characteristics for us to understand. Thanks to the growing number of discoveries, we now have enough data to study the physical processes that govern these objects. My research program addresses fundamental questions about the composition, origin and evolution of these planets. By inferring the composition of these objects we gain information about the location and timing of formation. Our research includes studying two aspects about formation: with theoretical models we aim to understand how atmospheric evaporation has shaped the envelopes of these planets, and by modeling the end-stages of formation and tying it to chemical composition, we will quantify the compositional outcomes of solid planets. This will allow us to understand how common an Earth-like and Mercury-like compositions are for planets around other stars. Furthermore, we know that planets evolve habitable conditions, and that Earth's thermal evolution has played a role in making it suitable for life. Super-Earths typically experience surface temperatures, heating budgets and mantle compositions that differ drastically from Earth and other solar system solid planets. Our goal is to generalize thermal evolution studies and understand mantle convection under generalized conditions appropriate for rocky/icy super-Earths. With the aim of helping future observations, we will couple mantle convection to outgassing of the atmosphere to trace out the pathways to habitability of terrestrial planets. This research program will help us understand the Earth and the Solar System planets in a broad planetary context.