The Inner Workings of Starbursts and Their Winds

自20世纪90年代中期以来，天文学家已经认识到，宇宙中的恒星形成并不是一成不变的，事实上，单位体积的恒星形成率在z~2达到峰值后一直在稳步下降。虽然仍不完全清楚，但人们认为这是由于来自宇宙网的原始气体流入的稳步减少，这是过去更有效的恒星形成模式，以及来自强烈恒星形成区域的大尺度银河风的影响。这项研究集中在高空间分辨率的亚/毫米波长线和对发生高效率恒星形成和相关的风驱动外流的局部星爆星系的连续观测，以更好地了解在其顶峰时期(即“宇宙正午”)驱动恒星形成的物理过程。这个项目将支持两名研究型研究生和一名本科生，后者参与一个辅助项目，该项目致力于增加少数族裔群体中STEM的参与。该项目利用高角度分辨率的亚/毫米级和射电观测本地星暴星系NGC253、M82和NGC4945，将促进对塑造它们演化的物理过程的了解。这项研究的一个关键目标是更好地理解恒星形成通过(例如)“猝灭”的物理学。在观测上限制了银河系规模的由恒星爆发和影响其命运的外流气体中的物理条件驱动的风驱动的外流中冷气的夹带。研究小组还将测量年轻的大质量星团的基本性质，提高我们对形成这些星团的恒星比例的了解，并确定星暴星系之间分子气体性质的差异。所有这些结果将导致更接近物理现实的星系演化数值模型。研究人员将把这些结果放在处于宇宙恒星形成顶峰的主序星系的背景下，通过比较新的大星系样本(迪纳摩)中局部恒星爆发的物理状态和空间分辨的分子属性。这一奖项反映了美国国家科学基金会的法定任务，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。

Astronomers have realized since the mid-1990s that the star formation in the Universe has not been constant, and that in fact, the star formation rate per unit volume has steadily decreased since attaining a peak at z ~ 2. While still not completely understood, this is thought to be due to a combination of a steady decrease in the inflow of pristine gas from the Cosmic Web, a more efficient mode of star formation in the past, and the effects of large-scale galactic winds from regions of intense star formation. This research centers on high spatial resolution sub/millimeter wavelength line and continuum observations of local starburst galaxies, where high efficiency star formation and associated wind-driven outflows occur, in order to better understand the physical processes driving star formation at its peak epoch (i.e., "cosmic noon"). This project will support two research graduate students and one undergraduate student, the latter participating in a side project working to increase STEM participation among minority populations.Using high angular resolution sub/millimeter and radio observations of the local starburst galaxies NGC 253, M82, and NGC 4945, this project will advance knowledge of the physical processes that shape their evolution. A key goal of this research is a better understanding of the physics of star formation “quenching" through (e.g.) observationally constraining the entrainment of cold gas in galactic scale wind-driven outflows powered by starbursts and the physical conditions in the outflowing gas that influence its fate. The research team will also measure basic properties of young, massive starburst clusters and improve our knowledge of the fraction of stars that form in them and determine how molecular gas properties vary among starburst galaxies. All these results will lead to more physically realistic numerical models of galaxy evolution. The researchers will place these results in the context of main sequence galaxies at the peak of cosmic star formation by comparing the physical state of the local starbursts with spatially resolved molecular properties in a new large galaxy sample (DYNAMO).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.