Advanced Multibeam Spectrometer for the GBT

NRAO Green Bank望远镜（GBT）是世界上最大的全可操纵射电望远镜，其工作波长短至几毫米。望远镜上的大部分观测时间用于谱线工作，但由于目前的光谱仪无法使前端接收器的全部功能发挥作用，因此输出受到严重限制。由加州大学伯克利分校和NRAO的PI Dan Werthimer及其合作者计划的新光谱仪将基于现代现场可编程门阵列技术和标准化的组件硬件，允许同时观测所有7个k波段（~1厘米）焦平面阵列（FPA）的双偏振馈源，或所有16个3毫米焦平面阵列的单偏振馈源。3 ghz瞬时带宽和32,768个光谱通道将提供高分辨率和多馈源光谱的新能力，支持GBT的新科学优先事项，包括搜索星际介质中的有机分子，测量宇宙演化的基本常数，研究恒星形成区域的动力学，以及测量银河系中心附近的脉冲星。新的光谱仪将成为GBT设施仪器的关键部分，确保全国天文学家，包括博士后天文学家和学生开放使用。通过提供更高的光谱分辨率和映射效率，该开发还将使广泛的科学努力成为可能，并且通过使用标准化（伯克利CASPER）硬件，该体系结构将易于直接维护和升级。最后，这个项目的发展将增加不断增长的开源硬件、软件和网关软件库，用于社区可用的科学信号处理应用程序。这项工作的资金由美国国家科学基金会天文科学部通过其先进技术和仪器项目提供。

The NRAO Green Bank Telescope (GBT) is the largest fully-steerable radio telescope in the world that operates at wavelengths as short as a few mm. A large fraction of the observing time on the telescope is used for spectral line work, yet the output is severely limited by the current spectrometer because it does not enable the full capabilities of the front-end receivers. A new spectrometer planned by PI Dan Werthimer and collaborators at the University of California - Berkeley and NRAO will be based on modern Field Programmable Gate Array technology and standardized component hardware to allow simultaneous observation with all 7 dual-polarization feeds of the K-Band (~1-cm) Focal Plane Array (FPA), or all 16 single-polarization feeds of the 3-mm FPA. The 3-GHz instantaneous bandwidth and 32,768 spectral channels of the proposed spectrometer will provide new capabilities in high-resolution and multi-feed spectroscopy, supporting new science priorities for the GBT, including searching for organic molecules in the interstellar medium, measuring fundamental constants through the evolution of the universe, investigating the dynamics of star-forming regions, and surveying for pulsars near the Galactic center. The new spectrometer is slated to become a key part of the facility instrumentation at the GBT, ensuring open access by astronomers nationwide, including postdoctoral astronomers and students. By providing much higher spectral resolution and mapping efficiency, the developments will also enable a broad array of scientific endeavors, and by utilizing standardized (Berkeley CASPER) hardware the architecture will be amenable to straightforward maintenance and upgrade. Finally, developments from this project will add to the growing library of open-source hardware, software, and gateware available for scientific signal processing applications available to the community. Funding for this work is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.