ngVLA Design & Development: FY2020

美国国家射电天文台（NRAO）一直在与天文学界合作开发下一代甚大阵列（ngVLA）。ngVLA被设想为一种干涉测量阵列，其灵敏度和空间分辨率比目前的VLA、甚长基线阵列（VLBA）和阿塔卡马毫米/亚毫米阵列（ALMA）高10倍，工作频率范围为1.2 - 116 GHz。该项目将在阵列内每个主要子系统的概念设计选择中结束，并允许过渡到这些子系统的初步设计。关键技术开发和风险降低活动将包括在内，以确保在选择中考虑可能降低成本或提高性能的新颖前沿技术。为期两年的项目以MREFC候选提案和系统设计结束，该系统设计已准备好接受NSF领导的概念设计审查（与NSF主要设施手册一致）。知识优势：ngVLA将是一个变革性的、多学科的科学仪器，它将通过对热谱线和连续发射的超灵敏成像，达到毫弧秒级的分辨率，以及前所未有的非热过程的宽带连续偏振成像，为宇宙打开一扇新的窗口。这些能力是解决现代天文学中广泛的关键问题的唯一手段，包括对类地行星形成的直接成像，对尘埃遮蔽的恒星形成和宇宙重子循环的研究，一直到秒差尺度到室女座星团，对推动恒星形成的分子气体进行宇宙普查，这些气体可以追溯到第一次光和宇宙再电离，在这个多信使天体物理学的新时代，探索从毫秒到几年的时间尺度上的时间现象的新技术。ngVLA将在亚毫米波段的ALMA和未来一期平方公里阵列（SKA-1）之间的光谱区域进行优化，以达到分米和更长的波长。更广泛的影响：ngVLA项目为学生培训提供了机会，增加了代表性不足群体的参与，为更广泛的美国研究社区带来了切实的利益（例如，数据档案访问和新技术的商业化），并对设施所在社区的环境和经济产生了积极影响。拟议的努力将为NRAO多样性和包容性办公室（ODI）以及教育和公共宣传（EPO）部门提供补充资金，以扩大其核心活动，包括ngVLA。受到积极影响的项目包括非裔美国人教学研究员（AATF）、国家天文学联合会（NAC）本科项目以及国家和国际交流（NINE）项目。除了更广泛的参与和教育影响外，ngVLA项目还将直接影响在新墨西哥州、亚利桑那州和德克萨斯州培养振兴美国西南部的高科技制造中心，包括精密机械制造和制造业。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。

The National Radio Astronomy Observatory (NRAO) has been working with the astronomical community on the development of the next-generation Very Large Array (ngVLA). The ngVLA is envisaged as an interferometric array with ten times greater sensitivity and spatial resolution than the current VLA, Very Long Baseline Array (VLBA) and the Atacama Millimeter/submillimeter Array (ALMA), operating in the frequency range of 1.2 - 116 GHz. This project will end in the conceptual design down-select for each major sub-system within the array, and allow the transition to the preliminary design of these subsystems. Critical technical development and risk reduction activities will be included to ensure that novel leading-edge technologies that may reduce cost or improve performance are considered in the down-select. The two-year project ends with a proposal for MREFC candidacy, and a system design that is ready for an NSF-led conceptual design review (consistent with the NSF Major Facilities Manual).INTELLECTUAL MERIT: The ngVLA will be a transformative, multi-disciplinary scientific instrument that will open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milliarcsecond-scale resolution, as well as unprecedented broad-band continuum polarimetric imaging of non-thermal processes. These capabilities are the only means with which to address a broad range of critical questions in modern astronomy, including direct imaging of Earth-like planet formation in the terrestrial zone, studies of dust-obscured star formation and the cosmic baryon cycle down to parsec-scales out to the Virgo cluster, undertaking a cosmic census of the molecular gas which fuels star formation back to first light and cosmic reionization, and novel techniques for exploring temporal phenomena on timescales from milliseconds to years in this new era of multi-messenger astrophysics. The ngVLA will be optimized for observations in the spectral region between the superb performance of ALMA at sub-mm wavelengths, and the future Phase I Square Kilometer Array (SKA-1) at decimeter and longer wavelengths. BROADER IMPACT: The ngVLA project offers opportunities for student training, increased participation of underrepresented groups, tangible benefits to the wider U.S. research community (e.g., data archive access and the commercialization of new technologies), and positive impacts to the environment and economy of the communities that host the facility. The proposed effort will provide supplemental funding to the NRAO Office of Diversity and Inclusion (ODI) and Education and Public Outreach (EPO) departments to expand their core activities to include the ngVLA. Programs that will be positively impacted include the African American Teaching Fellows (AATF), the National Astronomy Consortium (NAC) undergraduate program, and the National and the Inter-National Exchange (NINE) program. In addition to the broader participation and educational impacts, the ngVLA project will have a direct impact on fostering a revitalized U.S. high-tech manufacturing hub in the southwest, with precision machine fabrication and manufacturing in New Mexico, Arizona, and Texas.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.