How are HI Disks Fed? Probing the Drivers of Regulated Galaxy Growth

盘状星系通过其盘内的冷气体云形成恒星。随着恒星的形成，冷气体的含量减少。为了使星系继续形成恒星，它们必须从外部获得低温气体。从星系间空间吸积气体的过程叫做凝结。该项目将使用甚大阵列（VLA）和哈勃太空望远镜的观测结果来绘制冷盘气体和星系间气体的分布图，以便更好地了解冷凝过程。该项目将以35个附近的盘状星系为目标进行观测，并将结果与计算机模拟的星系生长和演化进行比较。来自这些观察的数据将被转换成3D可视化，用于公共和课堂环境。该项目将使用来自VLA和QSO吸收光谱的21厘米数据来追踪旋转的HI盘到大星系半径，这样他们就可以识别与圆盘旋转不一致的气体团块。他们将寻找凝结云的发生率与年轻恒星的流行和恒星反馈之间的相关性。VLA地图将与模拟的模拟图像进行比较，以便估计凝结云的来源。该项目将产生数据产品，这些产品将通过VLA-Disk网站提供给天文社区。他们还将制作交互式3D可视化，用于公共宣传和课堂内。这些互动工具的使用将在StarLab年度研讨会上介绍给当地高中教师，并通过对教师的调查来评估其有效性。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。

Disk galaxies form stars through clouds of cold gas in their disks. As the stars form, the cold gas content is reduced. In order for galaxies to continue to form stars, they must acquire cold gas from outside. The process of accreting gas from intergalactic space is called condensation. This project will use observations from the Very Large Array (VLA) and the Hubble Space Telescope to map out the cold disk gas and the infalling intergalactic gas in order to better understand the process of condensation. The project will target 35 nearby disk galaxies for their observations and will compare the results with computer simulations of the growth and evolution of galaxies. The data from these observations will be converted to 3D visualizations for use in public and classroom settings.The project will use 21-cm data from the VLA and QSO absorption spectroscopy to trace the rotating HI disk to large galactic radii so that they can identify gas clumps that are inconsistent with the rotation of the disk. They will look for a correlation between the incidence of condensing clouds and the prevalence of young stars and stellar feedback. The VLA maps will be compared to mock images from simulations in order to estimate the source of the condensing clouds. The project will produce data products that will be available to the astronomical community through the VLA-Disk website. They will also produce interactive 3D visualizations for use in public outreach and within the classroom. Use of these interactive tools will be introduced to local high-school teachers at an annual StarLab workshop and their effectiveness will be evaluated through surveys of the teachers.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.