CAREER: Tracing the flow of gas from the cosmic web onto galaxies

目前的星系形成理论预测，星系的气体供应是通过星系间介质和宇宙网的气体吸积不断补充的。对于低密度环境下的低质量星系，大部分气体沿着细丝落在星系盘上时保持低温。皮萨诺博士将使用单碟射电望远镜和下一代无线电干涉仪观察这些系统发出的微弱中性氢辐射。迄今为止，这样的观测已经揭示了许多星系周围的气体云，但推断的吸积率太低，无法维持恒星的形成。通过绘制星系周围的弥散气体，该项目将确定本地星系的气体吸积率，并利用星系周围气体的人口统计数据加上对单个系统的详细观察，将首次将氢与潮汐起源或冷吸积联系起来。为了帮助解决中学生在STEM学科上落后的学生成绩，皮萨诺博士和合作者将开发一个开放式的、基于探究的教育活动，“这些东西是什么？”这项活动将让西弗吉尼亚州的中学生参与到实际的天文研究中来，利用THINGS星系样本的多波长档案数据，随后有机会使用天网远程操作望远镜获取他们所采用星系的原始光学、红外和无线电数据。在整个活动中，训练有素的本科生和研究生将指导中学生。因此，这项活动将为各级学生提供启发和训练，使他们成为下一代天文学家和教育家。

Current theories of galaxy formation predict that the gas supply of galaxies is continuously replenished by the accretion of gas from the intergalactic medium and the cosmic web. For low-mass galaxies in low-density environments, most of this gas remains cool as it falls along filaments onto the galaxy disks. Dr. Pisano will observe faint neutral hydrogen emission from these systems using single-dish radio telescopes and next-generation radio interferometers. To date, such observations have revealed gas clouds around many galaxies, but the inferred accretion rates are too low to sustain star formation. By mapping the diffuse gas around galaxies, this project will determine the gas accretion rate onto local galaxies and, using the demographics of gas around galaxies plus detailed observations of individual systems, will associated the hydrogen with either a tidal origin or cold accretion for the first time. To help address lagging student achievement in STEM subjects amongst middle school students, Dr. Pisano and collaborators will develop an open-ended, inquiry-based educational activity, "What are those THINGS?" This activity will engage West Virginia middle school students in real astronomical research using archival multi-wavelength data on the THINGS galaxy sample followed by the opportunity to use the Skynet remotely-operable telescopes to acquire their own original optical, infrared, and radio data for their adopted galaxy. Throughout this activity, trained undergraduate and graduate students will mentor the middle school students. As such, this activity will provide inspiration and training to students of all levels to become the next generation of astronomers and educators.