U.S.- South Africa Collaboration: Catalyzing a Deep Neutral Hydrogen Survey with MeerKAT

理解星系是如何在宇宙时间内形成和演化的，是现代天体物理学的核心挑战之一。在过去的15年里，天文学家通过研究早期宇宙中遥远星系的恒星的性质，已经了解了很多；然而，关于它们气体的性质，尤其是氢以原子(而不是电离或分子)的形式存在的相对较冷和弥散的物质，人们所知要少得多。该项目将通过催化一项新的国际合作，朝着理解宇宙中的中性原子氢迈出重要的第一步。该项目已被批准利用南非正在建造的一系列射电望远镜进行5000小时的勘测。这个新的阵列被称为猫鼬，而新的调查采用了“用猫鼬阵列看遥远的宇宙”或“拉杜马”的名称。美国国家科学基金会的资助将允许12名美国科学家参加2011年底或2012年初在南非开普敦举行的拉杜马调查的首届“全员”合作会议。当地的东道主将是开普敦大学的Sarah Blyth博士，她与欧洲航天局的Benne Holwerda博士和新泽西州立大学的Andrew Baker博士共同担任拉杜马的领导职务。美国代表团将有学生参与，成员包括来自罗格斯大学、国家射电天文台、亚利桑那大学、加州大学伯克利分校、科罗拉多大学、新墨西哥大学、北卡罗来纳大学、威斯康星大学的代表，这个项目的学术价值主要来自一项调查的巨大科学潜力，该调查最终将能够在宇宙不到现在年龄的一半的时代探测到中性原子气体。这次合作的首次全体会议将汇集来自56人团队的射电、光学和理论天文学家，以确定调查的最佳策略，并为重点领域的重点准备工作奠定基础，如与其他望远镜获取补充数据和建立学生联合监督。由于猫鼬工程办公室设在开普敦，此次会议还将允许拉杜马科学家和猫鼬工程师进行面对面的讨论。拉杜马合作的更广泛影响包括有机会让美国科学家和学生参与新的国际研究合作。拉杜马团队的所有美国成员都有很好的监督学生的记录，并且都有有助于将来招募学生参加调查的预约。美国拉杜马团队中有一半与属于南部非洲光学大望远镜(SALT)合作伙伴关系的机构有关联，从而加强了这些机构与南非之间业已存在的联系，并促进了合作者之间的新关系。这一伙伴关系还将为南非的教育和推广带来机会。该奖项由美国国家科学基金会国际科学与工程办公室资助。

Understanding how galaxies form and evolve across cosmic time is one of the central challenges of modern astrophysics. In the last fifteen years, astronomers have learned a great deal about distant galaxies in the early universe by studying the properties of their stars; however, much less is known about the properties of their gas, especially the relatively cool and diffuse material in which hydrogen is atomic (rather than ionized or molecular) in form.This project will take an important first step toward understanding the universe's neutral atomic hydrogen by catalyzing a new international collaboration that has been approved to conduct a 5000-hour survey with an array of radio telescopes being built in South Africa. The new array is known as MeerKAT, and the new survey has adopted the name "Looking At the Distant Universe with the MeerKAT Array" or LADUMA. NSF funding will allow 12 U.S. scientists to attend the LADUMA survey's inaugural "all hands" collaboration meeting in Cape Town, South Africa in late 2011 or early 2012. The local host will be Dr. Sarah Blyth of the University of Cape Town, who shares leadership duties for LADUMA with Dr. Benne Holwerda of the European Space Agency and Dr. Andrew Baker of Rutgers, the State University of New Jersey.The U.S. delegation will feature student participation and include representation from Rutgers, the National Radio Astronomy Observatory, the University of Arizona, the University of California at Berkeley, the University of Colorado, the University of New Mexico, the University of North Carolina, the University of Wisconsin, and West Virginia University.The intellectual merit of this project derives principally from the immense scientific potential of a survey that will ultimately be able to detect neutral atomic gas at an epoch when the universe was less than half its present age. The collaboration's first "all hands" meeting will bring together radio, optical, and theoretical astronomers from across the 56-person team to determine the optimal strategy for the survey and to lay the groundwork for focused preparatory efforts in key areas, such as the acquisition of complementary data with other telescopes and the establishment of joint supervision of students. Because Cape Town is the location of the MeerKAT engineering office, the meeting will also allow face-to-face discussions between LADUMA scientists and MeerKAT engineers.The broader impacts of the LADUMA collaboration include an opportunity to engage U.S. scientists and students in a new international research collaboration. All U.S. members of the LADUMA team have strong records of supervising students, and all have appointments that will facilitate recruitment of students to the survey in the future. Half of the U.S. LADUMA team have affiliations with institutions that are part of the optical Southern African Large Telescope (SALT) partnership, strengthening the bonds that already exist between these institutions and South Africa and catalyzing new relationships among the collaborators. The partnership will also result in opportunities for education and outreach in S. Africa.This award is being funded by NSF's Office of International Science and Engineering.