On the origins and composition of planetesimals through studies of circumstellar disks

在理解行星是如何聚集在一起并与其他天体（如彗星和小行星）相互作用的过程中，一个基本的复杂因素是我们无法直接观察这些天体的形成和演化。新的设施现在正在打开一个关于拱星盘的新窗口，所有行星形成的位置，为我们提供了探测系统如何演化的能力，并测试了一些关于我们自己太阳系起源的关键假设。这项研究计划将针对关键的磁盘系统，利用这些磁盘中的气体和固体的测量来告知我们对太阳系最早期的理解。在太阳系内，对关键化学示踪剂的测量，例如氘（一种带有额外中子的氢的变体）与氢（D/H）的比率，是针对彗星和小行星进行的，以了解这些物体自形成以来如何在太阳系中移动。支撑这个模型的假设是，早期太阳盘的D/H比在太阳附近较低，而在更远的地方较高。利用最近发现的年轻系统，其中彗星和小行星的形成已经开始或完成，但气体盘仍然存在，我们将用阿尔马望远镜测量一些盘系统的D/H比，以验证早期太阳系模型的这一方面，从而提高我们对行星和盘（彗星和小行星）如何演变和相互作用的理解。此外，使用其他设施，如双子座行星成像仪（GPI）和即将发射的詹姆斯韦伯太空望远镜，我们将测量磁盘内部区域的气体运动，并将其与固体的位置进行比较，以解释系统如何通过碰撞和随时间推移的物质损失动态演变。利用这些数据，我们将限制行星系统内大型（行星）和小型（小行星和彗星）天体的迁移。 我的目标是最大限度地提高加拿大的阿尔马（阿塔卡马大型毫米/亚毫米阵列，第一个十亿美元的地面望远镜）和GPI磁盘科学的科学产出。由该提案资助的学生将增加在阿尔马和GPI被设计为擅长的关键领域之一工作的哥伦比亚研究人员的人数：行星系统在周星盘内的演化。

A fundamental complication in understanding how planets are assembled and interact with each other and other bodies (like comets and asteroids) has been our inability to directly observe the formation and evolution of these bodies. New facilities are now opening a new window on circumstellar disks, the location where all planets form, providing us with an ability to probe how systems evolve and to test some key assumptions about our own solar system's origins. This research proposal will target key disk systems to utilize the measurements of gases and solids in those disks to inform our understanding of the solar system's earliest times. Within the solar system, measurements of key chemical tracers, such as the ratio of deuterium, a variant of hydrogen with an extra neutron, to hydrogen (D/H) are made toward comets and asteroids to understand how those objects have moved around in the Solar System since their formation. Underpinning this model is the assumption that the D/H ratio in the early solar disk was low near the sun and higher further away. Using recently identified young systems in which comets and asteroid formation has begun or is complete but the gas disk remains, we will measure with the ALMA telescope the D/H ratio for a number of disk systems to verify this aspect of the early Solar System model, thereby enhancing our understanding of how the planets and disk (comets and asteroids) have evolved and interacted with each other. In addition, using other facilities like the Gemini Planet Imager (GPI) and the soon to be launched James Webb Space Telescope, we will measure the motions of gas in the inner regions of disks and compare them to the locations of solids in order to explain how the systems evolve dynamically through collisions and loss of material over time. Using these data, we will place constraints on the migration of large (planets) and small (asteroids and comets) bodies within planetary systems. My goal with this proposal is to maximize Canada’s scientific output of ALMA (the Atacama Large Millimeter/submillimeter Array, the first billion dollar ground based telescope) and GPI disk science. The students funded by this proposal will augment the population of Canadian-based researchers who work in one of the key areas of in which ALMA and GPI are designed to excel: evolution of planetary systems within circumstellar disks.