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The C-Band All Sky Survey: Separation of Diffuse Galactic Emissions at 5 GHz

 

Authors: M.O. Irfan, C. Dickinson, R.D. Davies, et al.    
Journal: MNRAS
Year: 2015
Download: ADS | arXiv


Abstract

We present an analysis of the diffuse emission at 5 GHz in the first quadrant of the Galactic plane using two months of preliminary intensity data taken with the C-Band All Sky Survey (C-BASS) northern instrument at the Owens Valley Radio Observatory, California. Combining C-BASS maps with ancillary data to make temperature-temperature plots we find synchrotron spectral indices of β=−2.65±0.05 between 0.408 GHz and 5 GHz and β=−2.72±0.09 between 1.420 GHz and 5 GHz for −10∘<|b|<−4∘, 20∘

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The C-Band All-Sky Survey (C-BASS): design and implementation of the northern receiver

 

Authors:

O. G. King,  Michael E. Jones,  E. J. Blackhurst, et al.    

Journal: MNRAS
Year: 2014
Download: ADS | arXiv


Abstract

The C-Band All-Sky Survey (C-BASS) is a project to map the full sky in total intensity and linear polarization at 5 GHz. The northern component of the survey uses a broadband single-frequency analogue receiver fitted to a 6.1-m telescope at the Owens Valley Radio Observatory in California, USA. The receiver architecture combines a continuous-comparison radiometer and a correlation polarimeter in a single receiver for stable simultaneous measurement of both total intensity and linear polarization, using custom-designed analogue receiver components. The continuous-comparison radiometer measures the temperature difference between the sky and temperature-stabilized cold electrical reference loads. A cryogenic front-end is used to minimize receiver noise, with a system temperature of ≈30K in both linear polarization and total intensity. Custom cryogenic notch filters are used to counteract man-made radio frequency interference. The radiometer 1/f noise is dominated by atmospheric fluctuations, while the polarimeter achieves a 1/f noise knee frequency of 10 mHz, similar to the telescope azimuthal scan frequency.