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

盘状星系通过盘状星云中的冷气体形成恒星。随着恒星的形成，冷气体的含量会减少。为了让星系继续形成恒星，它们必须从外部获得冷气体。从星际空间吸积气体的过程称为凝聚。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流入的星系间气体的地图，以便更好地了解凝聚过程。该项目将以附近的35个盘状星系为目标进行观测，并将结果与星系生长和演化的计算机模拟进行比较。来自这些观测的数据将被转换成3D可视化，用于公共和课堂环境。该项目将使用来自VLA和类星体吸收光谱的21厘米数据来追踪旋转的HI盘到大银河系半径，这样他们就可以识别与盘的旋转不一致的气团。他们将寻找凝聚云的发生率与年轻恒星的盛行和恒星反馈之间的关系。VLA图将与模拟的模拟图像进行比较，以估计凝聚云的来源。该项目将制作数据产品，通过VLA-DISK网站向天文学社区提供。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一年一度的StarLab研讨会上向当地高中教师介绍，并将通过对教师的调查来评估其有效性。该奖项反映了NSF的法定使命，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。

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.