Collaborative Research: Early Planet Formation in Embedded Disks

随着天文学家观察到越来越多尘土飞扬的原恒星盘，更全面地了解行星形成过程成为可能。这项工作是为了探索一种确定原行星盘结构的全新方法。该团队将使用CO同位素的光谱成像来绘制碳和氧同位素的浓度图。该小组将对现有的ALMA观测以及该小组将进行的新观测进行光谱研究。他们将研究螺旋、缝隙和环等结构。他们还将确定年轻的原恒星盘的气体组成，通过盘演化的不同阶段组成的演变，并确定中央原恒星的质量。这项工作的结果将为行星形成模型提供新的观测约束。根据这一计划，两篇博士论文将由代表人数不足的群体的学生完成。该计划还将支持夏威夷本地本科生在分析和硬件开发方面的暑期研究工作。外展活动包括面向高中生的公开演讲和夏令营项目。该团队将使用自己开发的名为原生行星盘和带有巨蟒的恒星(Pdspy)的最先进建模代码，从多光谱ALMA成像中提取关于原行星盘的结构信息。PDSPY代码模拟多波长观测数据集，特别是将通过该团队的ALMA大计划获得的ALMA图像，使用物理激励的开普勒盘旋转坍塌包络系统的全辐射传输模型，使用马尔可夫链蒙特卡罗或嵌套抽样等贝叶斯参数估计方法对参数空间进行严格采样。该团队将在盘形成和演化的不同时间点观察和研究原行星盘，从最初的形成到原恒星发展的T Tauri阶段。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

As astronomers observe more and more dusty proto-stellar disks, a fuller understanding of the process of planetary formation becomes possible. This work is to explore an entirely new method of determining structures in proto-planetary disks. The team will map out concentrations of carbon and oxygen isotopes using spectroscopic imaging of CO isotopologues. The team will conduct a spectroscopic study of existing ALMA observations as well as new observations to be made by the team. They will examine structures such as spirals, gaps and rings. They will also determine the gas composition of young proto-stellar disks, the evolution of composition through different phases of disk evolution and determine the mass of the central protostar. The results of this work will provide new observational constraints for models of planetary formation. Two PhD theses will be completed under this program, both by students from under-represented groups. This program will also support Hawaiian native undergraduate students for summer research work both in analysis and in hardware development. Outreach activities include public talks and summer camp programs for high-school students.The team will use a self-developed state-of-the-art modeling code called Protoplanetary Disks and Stars with Python (pdspy) to extract structural information about protoplanetary disks from multispectral ALMA imaging. The pdspy code models multi-wavelength observational datasets, particularly ALMA images like those to be obtained through the team’s ALMA Large Program, with full radiative transfer models of physically motivated Keplerian disk + rotating collapsing envelope systems using Bayesian parameter estimation methods such as Markov Chain Monte Carlo or Nested Sampling to rigorously sample parameter space. The team will observe and study protoplanetary disks at different points in disk formation and evolution, from initial formation into the T Tauri phase of protostellar development.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.