Radio polarimetry at decimetre wavelengths is the principal source of information on the Galactic magnetic field. The diffuse polarized emission is strongly influenced by Faraday rotation in the magneto-ionic medium and rotation measure is the prime quantity of interest, implying that all Stokes parameters must be measured over wide frequency bands with many frequency channels. The DRAO 26-m Telescope has been equipped with a wideband feed, a polarization transducer to deliver both hands of circular polarization, and a receiver, all operating from 1277 to 1762 MHz. Half-power beamwidth is between 40 and 30 arcminutes. A digital FPGA spectrometer, based on commercially available components, produces all Stokes parameters in 2048 frequency channels over a 485-MHz bandwidth. Signals are digitized to 8 bits and a Fast Fourier Transform is applied to each data stream. Stokes parameters are then generated in each frequency channel. This instrument is in use at DRAO for a Northern sky polarization survey. Observations consist of scans up and down the Meridian at a drive rate of 0.9 degree per minute to give complete coverage of the sky between declinations -30 degree and 90 degree. This paper presents a complete description of the receiver and data acquisition system. Only a small fraction of the frequency band of operation is allocated for radio astronomy, and about 20 percent of the data are lost to interference. The first 8 percent of data from the survey are used for a proof-of-concept study, which has led to the first application of Rotation Measure Synthesis to the diffuse Galactic emission obtained with a single-antenna telescope. We find rotation measure values for the diffuse emission as high as approximately 100 rad per square metre, much higher than recorded in earlier work.
GMIMS-DRAGONS: A Faraday Depth Survey of the Northern Sky Covering 350-1030 MHz
University of British Columbia, Okanagan Campus（不列颠哥伦比亚大学奥卡纳根校区）；Dominion Radio Astrophysical Observatory, Herzberg Research Centre for Astronomy and Astrophysics, National Research Council Canada（加拿大国家研究理事会赫茨伯格天文学与天体物理学研究中心 Dominion 射电天文台）；University of Western Ontario（韦仕敦大学（原西安大略大学））；University of Calgary（卡尔加里大学）；INAF-Istituto di Radioastronomia（意大利国家天体物理研究所射电天文研究所）；University of Waterloo（滑铁卢大学）；Caltech Owen’s Valley Radio Observatory（加州理工学院欧文谷射电天文台）；Chalmers University of Technology, Onsala Space Observatory（查尔姆斯理工大学翁萨拉空间天文台）；University of South Carolina（南卡罗来纳大学）；University of Tasmania（塔斯马尼亚大学）；Radboud University（拉德堡德大学）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切尔蒂天文台）
The Canadian Galactic Emission Mapper (CGEM): A Cosmic Microwave Foreground Experiment
University of British Columbia（不列颠哥伦比亚大学）；Johns Hopkins University（约翰斯·霍普金斯大学）；National Research Council Canada（加拿大国家研究委员会）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）
Initial LOFAR observations of Epoch of Reionization windows: II. Diffuse polarized emission in the ELAIS-N1 field
本研究的目的是在ELAIS-N1领域的偏振前景发射，并解决其可能的影响，从低频阵列-再电离时代（LOFAR-EoR）数据的宇宙学21厘米信号的提取。我们使用LOFAR的高波段天线来成像这个区域，并使用RM合成来解开银河系高纬度极化发射的结构。探测到的银河系辐射的亮度温度平均为4 K，偏振强度为-10至+13 rad m^-2（法拉第深度）。总偏振强度和偏振角显示出广泛的形态特征。我们还使用了韦斯特博克综合射电望远镜（WSRT）在350兆赫的图像相同的区域。LOFAR和WSRT图像显示出相似的复杂形态，在可比的亮度水平，但它们的空间相关性非常低。150 MHz时的分数极化（以总强度的百分比表示）为1.5%。在干涉测量数据中，总强度中没有漫发射的迹象，这与较高频率下的结果一致。LOFAR的宽频率范围、良好的角分辨率和灵敏度使其成为研究银河系偏振辐射的精密仪器，法拉第深度的分辨率为1-2 rad m^-2。在150 MHz和350 MHz下观察到的不同极化图案与沿各种法拉第薄发射区域中的视线扭曲的不同源分布一致。极化前景的存在是再电离时代实验的一个严重并发症。为了避免偏振发射泄漏到总强度中（这可能取决于频率），我们需要将整个视场的仪器偏振校准到1%的小部分。
RM-Tools: Software for Analyzing Polarized Radio Spectra
The Australian National University（澳大利亚国立大学）；University of Toronto（多伦多大学）；UNSW Sydney（新南威尔士大学悉尼分校）；The University of Sydney（悉尼大学）；SKA Observatory（平方公里阵列射电望远镜天文台）；National Research Council Canada（加拿大国家研究委员会）；National Astronomical Observatory of Japan（日本国立天文台）；Villanova University（维拉诺瓦大学）；University of California, Santa Cruz（加州大学圣克鲁兹分校）；Yunnan University（云南大学）；the University of Calgary（卡尔加里大学）；Observatoire de Paris（巴黎天文台）；Université PSL（巴黎文理研究大学）；CNRS（法国国家科学研究中心）；Sorbonne Université（索邦大学）；Université Paris Cité（巴黎西岱大学）
