MRI: Development of the Next Generation 211-373 GHz Receiver for the Arizona Radio Observatory’s Sub-mm Telescope

我们的大气层对某些无线电频率是透明的，天文学家可以通过这些频率收集重要的天体物理信息。通过这些射电窗口，我们可以观察恒星形成的最早阶段，尘埃和复杂分子的产生，这些物质孕育了恒星、行星，甚至可能是生命本身，并拍摄出最清晰的黑洞照片。亚利桑那州射电天文台的亚毫米望远镜(SMT)，位于Mt.亚利桑那州格雷厄姆是一个非常有能力的射电望远镜，位于一个很好的位置，但它的观测能力受到其老化系统的限制。该项目将为SMT开发一种新的接收系统。这些改进将提高SMT的观测速度，并使用尖端的商业信号处理技术，将记录的频率范围扩大16倍。该项目是一个国家研究组织和一个大学团体之间的合作，旨在通过推进亚毫米技术来提高双方和国家的技术和科学能力。它将为从高中到研究生院的学生以及博士后研究员提供新的研究和教育机会。它将为东亚利桑那州学院的新外展工具和教育机会提供资金，该学院为格雷厄姆县农村地区和圣卡洛斯阿帕奇保护区提供服务。新的SMT接收器将集成用于0.8 mm(275-373 GHz)频段的最先进的边带分离混音器。这些将由亚利桑那大学和国家射电天文台(NRAO)中央开发实验室长期合作开发，并将在弗吉尼亚大学的多功能微制造和可伸缩生物制造设施(IFAB)中制造。混频器将以“边带分离”的配置耦合，允许15分贝的镜像边带抑制，大大降低噪声温度并消除不必要的镜像线路污染。新的0.8毫米和目前的1.3毫米调音台将安装在一个共同的杜瓦中，从而能够在两个波段同时进行观测。接收器杜瓦将提供使用新型商用射频系统片上系统(RFSoC)设备构建的新光谱仪后端，该设备将数字化高达32 GHz的瞬时频谱带宽(每边带/偏振8 GHz)。与现有系统相比，接收器噪声和光谱仪带宽的改进将使SMT在0.8 mm波段的探测速度提高约50倍。这将使在天体物理学的许多领域进行新的测量成为可能，包括濒临崩溃的冷核心的结构，大质量恒星的后期阶段和行星状星云的流出，以及对生命至关重要的元素的处理。新的接收器将为许多美国和外国机构的大量天文学家以及EHT联盟提供增强的观测能力。此外，将有相当数量的研究生参与该工具的建设。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Our atmosphere is transparent to some radio frequencies through which astronomers can collect important astrophysical information. Through these radio windows we can observe the earliest stages of star formation, the creation of dust and complex molecules that seed stars, planets, and possibly even life itself, and make the sharpest pictures of black holes. The Sub-millimeter Telescope (SMT) of the Arizona Radio Observatory, located on Mt. Graham, AZ, is an extremely capable radio telescope at a good site, but its ability to observe is limited by its aging systems. This project will develop a new receiving system for the SMT. The improvements will both increase the observing speed of the SMT and use cutting edge commercial signal processing technology to broaden by a factor 16 the range of frequencies recorded. This project is a collaboration between a national research organization and a university group to enhance the technical and scientific capabilities of both, and of the nation, by advancing submillimeter technology. It will provide new opportunities for research and education to students from high school through graduate school, as well as postdoctoral fellows. It will fund new outreach tools and educational opportunities at Eastern Arizona College, which serves rural Graham County and the San Carlos Apache Reservation. The new SMT receiver will incorporate new, state-of-the-art sideband-separating mixers for the 0.8mm (275-373 GHz) band. These will be developed by a long-running collaboration between the University of Arizona and the National Radio Astronomy Observatory (NRAO) Central Development Lab, and will be fabricated at the University of Virginia’s Multifunctional Microfabrication and Scalable Biomanufacturing Facility (IFAB). The mixers will be coupled in a “sideband-separating” configuration, allowing for 15 dB rejection of the image sideband, greatly reducing the noise temperatures and removing unwanted image line contamination. The new 0.8 mm and current 1.3 mm mixers will be mounted in a common dewar, enabling simultaneous observations in the two bands. The receiver dewar will feed a new spectrometer backend built using novel, commercial radio frequency system on chip (RFSoC) devices, that will digitize up to 32 GHz of instantaneous spectral bandwidth (8 GHz per sideband/polarization). Compared to the existing system, the improvements in receiver noise and spectrometer bandwidth will increase the survey speed of the SMT by a factor of ~50 in the 0.8mm band. This will enable new measurements in many areas of astrophysics, including the structure of cold cores on the verge of collapse, the late stages of massive stars and the outflows of planetary nebulae, and the processing of elements critical to life. The new receiver will provide enhanced observational capabilities for a large number of astronomers at many US and foreign institutions, as well as to the EHT consortium. In addition, a substantial number of graduate students will be involved in the construction of the instrument.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.