Ultra-stable Wideband Heterodyne Spectrometers: Molecular Lines from Distant Galaxies

摘要利用加州理工学院亚毫米波天文台的原型光谱仪对遥远的河外星系核进行的测量表明，在近太赫兹频率下，有一个丰富的科学领域等待着大型地面望远镜的探索。 然而，对这一区域的探索将需要光谱仪具有更好的稳定性和带宽。该赠款支持建造一个专用的新仪器，以观测宽而弱的河外谱线。 索菲亚和FIRST天文台将利用部分开发成果。 这项工作将集中于立即进行的地面仪器的组成部分。 具体而言，3.5 GHz带宽，256通道互相关系统，面向超稳定，亚毫米光谱将被开发和测试。 这将需要对辐射计不稳定性的起源进行调查，并测试新的宽带外差光谱仪架构。

ABSTRACTMeasurements of distant extragalactic nuclei using a prototype spectrometer at the Caltech Submillimeter Observatory have shown that there is a rich field of science awaiting exploration with large ground-based telescopes at near-THz frequencies. Exploration of this regime, however, will require spectrometers with improved stability and bandwidth.This grant supports construction of a dedicated new instrument that will enable observations of wide, weak, extragalactic lines. Some of the development will be leveraged from SOFIA and FIRST observatories. This effort will concentrate on the components for immediate ground-based instrumentation. Specifically, a 3.5 GHz bandwidth, 256 channel cross-correlator system geared to ultra-stable, submillimeter spectroscopy will be developed and tested. This will require an investigation into the origins of radiometer instabilities, and tests of new wideband heterodyne spectrometer architectures.