HI in the Local Universe

半个多世纪以来，21cm的中性氢线（HI）一直是星系研究和宇宙学的主要观测工具之一。它已经以越来越高的灵敏度和分辨率用于研究我们自己的星系和其他盘状系统的结构，它们与其他星系的相互作用，宇宙的大尺度结构，以及高红移系统的物理条件。最近21厘米探测器、光谱仪和多馈源系统的发展极大地扩展了参数空间的可访问体积和我们快速采样的能力。阿雷西博望远镜的新七馈源阵列使它能够以前所未有的体积和低质量水平研究HI宇宙。本研究的第一部分将探索的微弱的一端嗨质量函数,和第二部分作为一个试点,将开展,发展必要的分析工具,并处理,使公开可访问的产品,(a)的快速调查阿雷西博嗨天空,(b) medium-deep调查室女座星系团的星系,(c)深隐带银河系外的嗨调查,所有使用阿雷西博饲料阵列系统。所有这三个调查都有助于与几个不同的项目进行协同协调，而不仅仅是目前的项目，包括银河系结构和高速云的研究，脉冲星搜索和无线电连续瞬变的探测。软件工具和数据产品将提供给社区，这项研究工作将为培训新一代美国单碟射电天文学家提供肥沃的土壤。

AST-0307661GiovanelliFor over half a century, the 21cm line of neutral hydrogen (HI) has been one of the main observational tools for galactic studies and cosmology. It has been used with ever-increasing sensitivity and resolution to investigate the structure of our own Galaxy and of other disk systems, their interactions with other galaxies, the large-scale structure of the Universe, and the physical conditions of high redshift systems. The recent evolution of 21 cm detectors, spectrometers and multi-feed systems has dramatically expanded both the accessible volume of parameter space and our ability to sample it quickly. The new seven-feed array for the Arecibo telescope enables it to study the HI Universe to unprecedented volumes and low mass levels.The first part of this research will explore the faint end of the HI mass function, and act as a pilot for the second part, which will carry out, develop the necessary analysis tools for, and process and make publicly accessible the products of, (a) a fast survey of the Arecibo HI sky, (b) a medium-deep survey of the Virgo cluster of galaxies, and (c) a deep extragalactic HI survey in the Zone of Avoidance, all using the Arecibo feed array system. All three surveys lend themselves to synergistic coordination with several different projects, not just the present ones, including studies of Milky Way structure and high velocity clouds, a pulsar search, and the detection of radio continuum transients.The software tools and data products will be made available to the community, and the research work will provide fertile ground for the training of a new generation of US-based single-dish radio astronomers.