The C-Band All-Sky Survey: Instrument design, status, and first-look data

TL;DR

The C-Band All-Sky Survey (C-BASS) is developing sensitive 5 GHz maps of the sky's diffuse Galactic emission to aid in foreground subtraction for Cosmic Microwave Background studies, with ongoing observations and initial data analysis.

Contribution

This paper details the design, construction, and initial data of the C-BASS instrument, a novel all-sky survey at 5 GHz for astrophysical foreground mapping.

Findings

First-look data demonstrates the instrument's capability to map Galactic emission.

Initial maps show promising sensitivity and resolution for foreground separation.

The survey provides valuable data for CMB polarization studies.

Abstract

The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.