The C-Band All Sky Survey: Diffuse Galactic Emission and CMB Polarization

C波段全天探测(C-BASS)是一项在5 GHz范围内对整个天空进行的总强度和线偏振的无线电探测。调查的北部将于2012年使用欧文斯河谷射电天文台6.1米天线上的低温接收器完成，该接收器针对总强度和线极化进行了优化。2012-2013年将在南非使用7.6米天线上的类似接收器进行平行的南方调查。该奖项支持完成北部调查以及公布和解释调查结果。C-BASS将是第一次对漫射银河系辐射进行全天探测，其频率低到足以被同步辐射主导，但高到足以不受法拉第旋转效应的影响。它将提供有关星际介质、银河系磁场和辐射机制的新信息。为了改善极化宇宙微波背景(CMB)与前景发射的分离，还需要C-BASS数据。CMB的极化是由WMAP和Planck卫星以及几个目前和未来的地面和气球实验测量的。这些实验的一个主要目标是测量B模偏振信号，预计它将提供关于暴涨时代的信息--特别是暴涨的能量尺度--以及关于能量大统一的物理学的信息。这就要求CMB与前景发射的分离比我们目前对银河系前景的理解更准确。C-BASS数据将显著提高前景减去的精度。这项调查是与牛津大学和曼彻斯特大学(英国)、罗兹大学和哈特劳大学(南非)以及KACST(沙特阿拉伯)的团体合作进行的。在国家科学基金会、牛津大学和曼彻斯特大学的支持下，北部调查的接收器已经建造并部署在OVRO。南部接收器的建设得到了牛津、曼彻斯特和KACST的支持。C-Bass天空地图将在完成后不久免费提供。学生将参与仪器的设计和建造，以及观测和数据分析。C-BASS团队的成员参与了欧文斯山谷射电天文台广泛外展项目的开发和执行。

The C-Band All Sky Survey (C-BASS) is a radio survey at 5 GHz of the entire sky in total intensity and linear polarization. The northern part of the survey will be completed in 2012 using a cryogenic receiver, optimized for both total intensity and linear polarization, on a 6.1-meter antenna at the Owens Valley Radio Observatory. A parallel southern survey will be conducted in 2012-2013 using a similar receiver on a 7.6-meter antenna in South Africa. This award supports the completion of the northern survey and the publication and interpretation of the results. The C-BASS will be the first all-sky survey of diffuse Galactic emission at a frequency low enough to be dominated by synchrotron radiation but high enough to be uncorrupted by Faraday rotation effects. It will provide new information about the interstellar medium, the Galactic magnetic field, and radiation mechanisms. The C-BASS data are also needed to improve the separation of the polarized cosmic microwave background (CMB) from foreground emission. The CMB polarization is measured by the WMAP and Planck satellites, and by several current and future ground-based and balloon-borne experiments. A major goal for these experiments is to measure the B-mode polarization signal, which is expected to provide information about the epoch of inflation - in particular, the energy scale of inflation - and about physics at grand unification energies. This requires that the CMB is separated from foreground emission with higher accuracy than it is possible with our current understanding of Galactic foregrounds. The C-BASS data will significantly improve the accuracy of foreground subtraction. The survey is conducted in collaboration with groups at the Universities of Oxford and Manchester (UK), Rhodes University and HartRAO (South Africa), and KACST (Saudi Arabia). The receiver for the northern survey has been constructed and deployed at OVRO with support from the NSF and Oxford and Manchester universities. Construction of the southern receiver has been supported by Oxford, Manchester, and KACST. The The C-BASS sky maps will be made freely available soon after completion. Students are involved in the design and construction of the instrumentation as well as the observations and data analysis. Members of the C-BASS team participate in the development and execution of broad outreach programs at The Owens Valley Radio Observatory.