Streamers: Funneling Material from Envelopes to the Youngest Planet-forming Disks

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。多米尼克·塞古拉-考克斯被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在德克萨斯大学开展研究和教育项目。塞古拉-考克斯将通过观测探索“流带”的特性，并将观测结果与原恒星质量吸积的模拟结果进行比较。“流带”是一种长而薄的漏斗，连接着年轻原恒星的出生包层和盘之间的物质。这项研究的结果将使天文学家了解物质是如何被吸积到原恒星上的，以及在恒星和行星形成的早期阶段，飘带扮演了什么角色。对于该项目的教育部分，Segura-Cox将为农村和社会经济弱势社区的初中和高中教师开发一个以天文学为主题的系列研讨会。该项目将对不对称飘带进行无线电干涉观测，以研究它们的化学成分、发生情况，以及它们将物质吸积到形成行星的圆盘上的距离。通过测量流带的化学成分，并将其与系外行星的成分进行比较，将评估流带物质直接并入行星的可能性。利用正在进行的调查，将系统地确定具有拖缆的原恒星的比例，以评估拖缆是否是行星形成盘的常见质量吸积途径。通过后续观测，将确定从云到盘的流光的全部范围。将观测结果与模拟结果进行比较，可以确定质量流入率、磁场强度以及随时间的流光化学演变。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Dominique Segura-Cox is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to conduct a program of research and education at the University of Texas. Segura-Cox will observationally explore the properties of “streamers” – long, thin funnels connecting material between the natal envelopes and disks of young protostars – and compare the observations with simulations of mass accretion in protostars. Results from this study will allow astronomers to understand how material is accreted onto protostars and what role streamers play in the early stages of star and planet formation. For the education component of this project, Segura-Cox will develop an astronomy-themed seminar series for middle school and high school teachers in rural and socioeconomically disadvantaged communities.This project will conduct radio interferometric observations of asymmetric streamers to study their chemical composition, occurrence, and from how far away they accrete material into planet-forming disks. By measuring the chemical composition of the streamers and comparing it to exoplanet compositions, the likelihood of streamer material being directly incorporated into planets will be assessed. Using ongoing surveys, the proportion of protostars with streamers will be systematically determined to assess whether streamers are a common mass-accretion pathway for planet-forming disks. Using follow-up observations, the full extent of streamers from clouds to disks will be determined. Comparing observations with simulations will permit determination of mass infall rates, magnetic field strengths, and streamer chemical evolution with time.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.