MRI: Development of a State-of-the-Art Multiband Receiver for Arizona Radio Observatory's New ALMA Antenna

MRI：为亚利桑那射电天文台的新型 ALMA 天线开发最先进的多频段接收器

• 批准号: 1531366
• 负责人: Lucy Ziurys
• 金额: $ 96.13万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1531366&HistoricalAwards=false
• 关键词: MRI; Development; State; Art; Multiband

As part of the development phase of the Atacama Large Millimeter Array (ALMA), two 12 meter ALMA prototype antennas (APA) were constructed for evaluation and testing, and installed at the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA) site in Socorro, New Mexico. After completion of the ALMA testing and evaluation phase, the Arizona Radio Observatory (ARO) at the University of Arizona (UA) acquired one of the two APA telescopes. After acquisition, the UA moved their APA to Kitt Peak, replacing the 40-year-old 12-m telescope, and rechristening the telescope as the new Arizona Radio Observatory (ARO) 12 m. The subject proposal funds a modern, multi-wavelength receiver system which will realize the full scientific potential of the new ARO 12 m antenna. The receiver will cover the 1-4 mm wavelength range in four separate bands, and will enable a broad range of astronomical research including spectroscopy of molecular clouds and planetary nebulae, astrobiological studies of disks and pre-biotic molecules, and the study of black holes. The new receiver and 12 m antenna will have a broad user base with U.S. astronomers and scientists from universities and national labs, the Event Horizon Telescope consortium, and the European Southern Observatory (ESO). As part of this program ARO will allocate 28 days of observing time per year to the general U.S. community to access ARO's unique northern hemisphere observing capability and to enable pathfinder science for ALMA. The program will incorporate significant student training at all levels, from high school through graduate school. This telescope, along with the ARI 10 m telescope on Mt Graham, are perhaps the only remaining general purpose radio telescopes operated by a US university. As such, they are among the few remaining opportunities for direct student involvement in radio telescope instrumentation and operations. The dual-polarization 4-band receiver will cover the astronomically important atmospheric windows at 1, 2, 3, and 4 mm wavelength regions well suited to the Kitt Peak site. The 3 (84-116 GHz), 2 (130-180 GHz) and 1 mm (211-275 GHz) bands will employ ALMA-type, sideband-separating (SBS), superconducting (SIS) mixers, which represent the world's best in sensitivity and stability. SBS 2 mm mixers will be developed in collaboration with the National Radio Astronomy Observatory (NRAO) Central Development Lab (CDL) to cover a band scientifically important and well matched to the Kitt Peak site. The mixer chip will be a series array of four SIS junctions, similar to ALMA Band 6, and will be fabricated by the University of Virginia Microfabrication Lab (UVML). The 4 mm band (67-90 GHz) will utilize NRAO HFET amplifiers, previously tested on the old ARO 12 m. This system will also be SBS through an E-band down-converter developed by ARO. The 3 mm mixers are already in ARO's possession and the 1 mm devices will be obtained from NRAO. The mixers/amplifiers will be mounted in the same dewar using a modular design with each band and associated optics positioned on a separate plate. The receiver system will bolt onto the flange of the antenna cabin at the secondary focus. The spectral-line control system is fully operational at the new 12 m and will accommodate the new receiver with minimal modification. The new receiver will be used mainly for spectroscopic observations of interstellar and circumstellar molecules, and will: i) cover important molecular transitions, such as the J=1 - 0 lines of CO, HCN, N2H+, H2CO, and HCO+, used widely as density and temperature tracers in interstellar gas; and ii) provide wider frequency coverage necessary for many astrochemical programs. A major focus will be the investigation of the extent of molecular matter in the Galaxy. The subject work will redefine translucent cloud boundaries using low-level CO emission, characterize dense cloud cores chemically and physically, probe the sky as seen by Planck, and investigate hybrid gaseous/debris disks. The surprisingly rich chemical content of planetary nebulae and its connection to the diffuse interstellar medium will be further investigated. Combined with laboratory spectroscopy, the molecular carriers of the biogenic element phosphorus will be sought. The ARO 12 m will also join the Event Horizon Telescope for 1 mm VLBI observations, improving overall sensitivity and adding an intermediate baselines for probing the larger scale structure around black holes.

作为Atacama大毫米阵列（ALMA）开发阶段的一部分，建造了两个12米的Alma原型天线（APA）进行评估和测试，并安装在新墨西哥州Socorro的国家无线电天文学天文台（NRAO）非常大的阵列（VLA）。 ALMA测试和评估阶段完成后，亚利桑那大学（UA）的亚利桑那无线电天文台（ARO）获得了两种APA望远镜之一。收购后，UA将其APA移至基特峰（Kitt Peak），取代了40岁的12米望远镜，并将望远镜作为新的亚利桑那无线电天文台（ARO）12 m。该主题提出了一个现代的多波长接收器系统，该系统将实现新的Aro aro 12 m天线的全部科学潜力。接收器将在四个单独的频段中覆盖1-4 mM波长范围，并将实现广泛的天文研究，包括分子云和行星星云的光谱，磁盘和益生元分子的天体生物学研究以及黑洞的研究。新的接收器和12 m天线将拥有广泛的用户基础，来自大学和国家实验室，活动地平线望远镜财团和欧洲南方天文台（ESO）的美国天文学家和科学家。作为该计划的一部分，ARO将每年分配28天的观察时间，以访问ARO独特的北半球观察能力，并为Alma提供探路者科学。该计划将在高中到研究生院进行各个级别的大量学生培训。这款望远镜以及Graham山上10 m的ARI望远镜也许是美国大学运营的唯一剩下的通用射电望远镜。因此，它们是直接学生参与射电望远镜仪器和操作的剩余机会之一。 双极化4波段接收器将在1、2、3和4 mm波长区域覆盖天文重要的大气窗，非常适合Kitt Peak位点。 3（84-116 GHz），2（130-180 GHz）和1 mm（211-275 GHz）频带将采用ALMA型，侧带分离（SBS），超导（SIS）搅拌机，这代表世界上最佳的灵敏度和稳定性。 SBS 2 MM搅拌机将与国家射电天文台（NRAO）中央开发实验室（CDL）合作开发，以覆盖科学重要的乐队，并且与Kitt Peak仪式非常匹配。混音器芯片将是一个由四个SIS连接的系列阵列，类似于Alma Band 6，并将由弗吉尼亚大学微加工实验室（UVML）制造。 4 mM频带（67-90 GHz）将利用NRAO HFET放大器，以前在旧的ARO 12 m上进行了测试。该系统还将通过ARO开发的电子波段向下连接器为SB。 3毫米搅拌机已经在ARO的所有权中，将从NRAO获得1毫米设备。混合器/放大器将使用模块化设计将其安装在同一露水中，并将每个频带与位于单独板上的相关光学器件安装在同一露水中。接收器系统将在次级焦点处螺栓固定在天线机舱的法兰上。光谱线控制系统在新的12 m处完全运行，并将以最小的修改适应新的接收器。新的接收器将主要用于星际和室内分子的光谱观测，并且将：i）覆盖重要的分子过渡，例如j = 1-0行的CO，HCN，N2H+，N2H+，H2CO和HCO+，广泛用作密度和密度和温度托盘的固定气体中的密度和温度。 ii）提供许多天文学程序所需的更广泛的频率覆盖率。主要重点是研究星系中分子物质的程度。主题工作将使用低级CO发射重新定义半透明的云边界，以化学和物理的方式表征密集的云核，探测普朗克所见的天空，并研究混合气体/碎屑磁盘。行星星云的令人惊讶的化学含量及其与弥漫性星际培养基的联系将得到进一步研究。将寻求生物元素磷的分子载体结合实验室光谱。 ARO 12 m还将连接事件范围的望远镜进行1 mM VLBI观测，提高了整体灵敏度并添加了一个中间基准，以探测黑洞周围较大规模的结构。