Collaborative Research: ACES Galactic Center Mass Flow

我们银河系的中心是动态的，恒星在分子气体云中形成。气体流动的压力调节着恒星的形成过程。当气体进出星系中心时，星系就会成长和变化。气体流形成新的恒星，为中心的超大质量黑洞提供能量，并以高能射流的形式喷射出质量。银河系中心是研究气体流动生命周期的最近和最好的实验室。研究小组将绘制第一张横跨整个银河系中心的高分辨率气体图。通过同时绘制气体运动和恒星形成的分布，研究小组将揭示这些过程是如何联系在一起的。这将是我们理解驱动所有星系中心活动周期的物理学的重大进步。此外，这项工作将支持创建一个项目，以支持在本科和研究生院之间过渡的一年代表性不足的学生。学生们将被纳入这项研究合作，并将接受数据分析培训和有针对性的指导。美国国家科学院“2020年代天文学和天体物理学发现之路”报告中的一个重点研究领域是对大尺度和小尺度宇宙质量流的研究。银河系的中心区域，被称为中央分子区（CMZ），是这些研究的一个独特的生态系统。CMZ是唯一一个可以同时探索从千秒差距缩小到原恒星盘的气体流动的地方。该团队将领导ALMA CMZ勘探调查（ACES）的关键部分，这是ALMA调查整个银河系中心的大型项目，并将首次对星系核的质量流进行全面测量。这个项目是一个前所未有的大观测区域和高分辨率成像的结合。研究人员将对分子气体和原恒星的质量进行全面普查，其规模跨越四个数量级，并利用十多种分子示踪剂表征伴生气体的运动学。这项工作的成果将包括CMZ中扩展（扩散）和紧凑（密集）质量分量的目录，以及气体通过CMZ的完整运动学模型。最终，这个项目将对流入、流出、恒星形成和中央超大质量黑洞的吸积速率进行确定的测量。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。

The center of our Milky Way Galaxy is dynamic, with stars forming in clouds of molecular gas. The pressure on the flow of gas regulates the star formation process. As gas moves in and out of galaxy centers, the galaxies grow and change. Gas flows form new stars, feed the central supermassive black hole, and eject mass in energetic outflows. The Milky Way center is the nearest and best laboratory for studying the life cycle of gas flows. The team of investigators will make the first high resolution maps of gas across the entire Milky Way center. By simultaneously mapping the gas motions and the distribution of star formation, the team will reveal how these processes are connected. This will be a significant advance in our understanding of the physics that drive the activity cycle in all galaxy centers. In addition, this work will support the creation of a program to support underrepresented students in the transition year between undergraduate and graduate school. Students will be integrated into this research collaboration and will receive data analysis training and targeted mentoring.A key research area in the National Academy’s “Pathways to Discovery in Astronomy and Astrophysics for the 2020s” report is the study of cosmic mass flows on large and small scales. The center region of the Milky Way, called the Central Molecular Zone (CMZ) is a unique ecosystem for these studies. The CMZ is the only location where gas flows from kilo-parsec scales down to proto-stellar disks can be explored simultaneously. The team will lead critical parts of the ALMA CMZ Exploration Survey (ACES), an ALMA large program to survey the entire Milky Way center and will make the first comprehensive measurement of mass flows in a galaxy nucleus. This program represents an unprecedented combination of a large observing area with high-resolution imaging. The investigators will conduct a complete census of the mass in molecular gas and protostars spanning four orders of magnitude in size scale and characterize the associated gas kinematics with more than a dozen molecular tracers. Products of this work will include a catalog of extended (diffuse) and compact (dense) mass components in the CMZ, as well as a complete kinematic model of gas motions through the CMZ. Ultimately, this project will make the definitive measurements of the rates of inflow, outflow, star formation, and accretion toward the central supermassive black hole.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.