大质量恒星形成早期阶段大样本高分辨率观测:星前核搜寻和各演化阶段的多尺度动力学

大质量恒星形成过程依然扑朔迷离，一直是天体物理研究的前沿问题之一。大质量星前核搜寻及大质量恒星形成动力学研究是理解其形成的关键。传统的搜寻认为大质量星前核主要存在于红外暗云中，但现有观测表明红外亮云中也存在。此外，主流研究偏爱小尺度(云核/团块<1pc)的大质量恒星形成动力学，但在更大尺度(分子云>1pc)上也很重要。瞄准这些紧迫问题，有机结合ALMA-ATOMS@3mm(关联小尺度)大样本高分辨率谱线和连续谱数据以及单天线Mopra@3mm(大尺度)谱线数据，本项目改变传统思维：1）在红外亮云环境中系统地搜寻大质量星前核，2）统计研究大质量恒星形成早期阶段(星前核至致密电离氢区)的多尺度(0.03-3pc)动力学(如物质下落)过程。目的是拓展现有可信度高的大质量星前核候选样本，探索普遍性的动力学观测特征及演化规律，最终对现有大质量恒星形成模型提供观测检验和约束、并加深理解其形成物理图景。

High-mass star formation is still far from being understood, and thus has been the subject of the frontier studies in astrophysics. Both searching for high-mass prestellar cores and studying the dynamics related to high-mass star formation processes are crucial steps toward understanding the high-mass star formation scenario. Traditional searches for high-mass prestellar cores have been preferentially biased toward the infrared (IR) dark clouds, yet, the presence of such cores in IR bright clouds has also been reported. Moreover, previous studies have often been focused on the small-scale (i.e., core/clump<1pc) dynamics of high-mass star-forming systems, however, the larger-scale (i.e., clouds>1pc) dynamics has also been reported increasingly to be of great importance. Focusing the above pressing issues, this program will take advantage of the first-hand, very competitive ALMA-ATOMS data (related to small-scale physics) that consist of high-resolutions of both continuum and a number of spectral lines at 3mm in high quality. Leveraging them, this program will proceed in a different way than the traditional studies 1) to systematically search for high-mass prestellar cores in IR bright clouds, 2) with the complementary Mopra 3mm line data (related to large-scale physics), to investigate statistically the multi-scale dynamics (e.g., infall motions from cloud, clump to core) of the early stages of high-mass star formation (i.e., from prestellar to compact Hii regions). Through these studies, we expect to 1) contribute to the population of the current candidate high-mass prestellar cores, 2) explore a general description of the dynamics feature of high-mass star formation and its potential evolutionary trend, 3) and ultimately examine the existing high-mass star formation theories and put several observational constraints to them.