Collaborative Research: Early Planet Formation in Embedded Disks

随着天文学家观察到越来越多的尘埃原恒星盘，对行星形成过程的更全面理解成为可能。这项工作是探索一种全新的方法来确定原行星盘的结构。该团队将利用CO同位素的光谱成像绘制出碳和氧同位素的浓度。该小组将对现有ALMA观测结果以及该小组即将进行的新观测结果进行光谱研究。他们将检查螺旋、缝隙和圆环等结构。他们还将确定年轻的原恒星盘的气体组成，通过磁盘演化的不同阶段组成的演变，并确定中心原恒星的质量。这项工作的结果将为行星形成模型提供新的观测约束。两篇博士论文将在该项目下完成，均由来自代表性不足群体的学生完成。该项目还将支持夏威夷本土本科生进行分析和硬件开发方面的暑期研究工作。拓展活动包括公开演讲和高中生夏令营项目。该团队将使用自行开发的最先进的建模代码，称为原行星盘和恒星与Python (pdspy)，从多光谱ALMA成像中提取有关原行星盘的结构信息。pdspy代码对多波长观测数据集进行建模，特别是通过团队的ALMA大型程序获得的ALMA图像，使用物理驱动的开普勒盘+旋转坍缩包络系统的完整辐射传输模型，使用贝叶斯参数估计方法（如马尔可夫链蒙特卡罗或嵌套采样）对参数空间进行严格采样。该小组将观察和研究原行星盘形成和演化的不同阶段，从最初的形成到原恒星发展的金牛座T阶段。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.