BICEP2 and Keck Array operational overview and status of observations

TL;DR

The paper provides an overview of the BICEP2 and Keck Array experiments, their deployment, operational status, and initial results in measuring CMB polarization to detect signatures of cosmic inflation.

Contribution

It presents the operational details, sensitivity improvements, and preliminary polarization maps from the BICEP2 and Keck Array experiments.

Findings

Sensitivity improvements after optimization

Preliminary polarization maps obtained

Deployment and operational status updated

Abstract

The BICEP2 and Keck Array experiments are designed to measure the polarization of the cosmic microwave background (CMB) on angular scales of 2-4 degrees (l=50-100). This is the region in which the B-mode signal, a signature prediction of cosmic inflation, is expected to peak. BICEP2 was deployed to the South Pole at the end of 2009 and is in the middle of its third year of observing with 500 polarization-sensitive detectors at 150 GHz. The Keck Array was deployed to the South Pole at the end of 2010, initially with three receivers--each similar to BICEP2. An additional two receivers have been added during the 2011-12 summer. We give an overview of the two experiments, report on substantial gains in the sensitivity of the two experiments after post-deployment optimization, and show preliminary maps of CMB polarization from BICEP2.