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无线电频率收集重要的天体物理信息。 通过这些无线电窗口，我们可以观察到星星形成的最早阶段，尘埃和复杂分子的产生，这些分子孕育了恒星、行星，甚至可能是生命本身，并拍摄出黑洞最清晰的照片。亚利桑那射电天文台的亚毫米望远镜（SMT），位于Mt。位于亚利桑那州的格雷厄姆是一个非常有能力的射电望远镜，但它的观测能力受到其老化系统的限制。本项目将为SMT开发一个新的接收系统。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机构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。它将为东亚利桑那学院提供新的外展工具和教育机会，该学院为格雷厄姆县和圣卡洛斯阿帕奇保留地提供服务。新的SMT接收器将采用最先进的0.8 mm（275-373 GHz）频段边带分离混频器。这些将由亚利桑那大学和国家射电天文台（NRAO）中央开发实验室之间的长期合作开发，并将在弗吉尼亚大学的多功能微制造和可扩展生物制造设施（IFAB）制造。混频器将耦合在一个“边带分离”的配置，允许15 dB的镜像边带抑制，大大降低噪声温度和消除不必要的镜像线污染。新的0.8毫米和现有的1.3毫米混频器将安装在一个共同的杜瓦瓶，使两个波段的同时观察。接收器杜瓦将为使用新型商用射频片上系统（RFSoC）器件构建的新频谱仪后端提供信号，该频谱仪将提供高达32 GHz的瞬时频谱带宽（每个边带/极化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的测量速度在0.8mm波段提高约50倍。这将使天体物理学许多领域的新测量成为可能，包括处于崩溃边缘的冷核结构，大质量恒星的后期阶段和行星状星云的外流，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，大量的研究生将参与仪器的建设。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.