Cosmic Microwave Background Science at Commercial Airline Altitudes

TL;DR

This paper investigates the use of the Airlander 10 hybrid air vehicle at airline altitudes for high-fidelity, multi-frequency CMB polarization measurements, aiming to improve detection of primordial gravitational waves by better foreground cleaning.

Contribution

It introduces a novel platform for CMB observations at high altitudes, optimizing detector distribution to enhance foreground removal, complementing existing and ongoing surveys.

Findings

Airlander 10 can effectively observe frequencies above 220 GHz for dust cleaning.

Optimized detector distribution improves foreground removal at various altitudes.

The platform complements existing CMB and foreground surveys.

Abstract

Obtaining high-sensitivity measurements of degree-scale cosmic microwave background (CMB) polarization is the most direct path to detecting primordial gravitational waves. Robustly recovering any primordial signal from the dominant foreground emission will require high-fidelity observations at multiple frequencies, with excellent control of systematics. We explore the potential for a new platform for CMB observations, the Airlander 10 hybrid air vehicle, to perform this task. We show that the Airlander 10 platform, operating at commercial airline altitudes, is well-suited to mapping frequencies above 220 GHz, which are critical for cleaning CMB maps of dust emission. Optimizing the distribution of detectors across frequencies, we forecast the ability of Airlander 10 to clean foregrounds of varying complexity as a function of altitude, demonstrating its complementarity with both existing (Planck) and ongoing (C-BASS) foreground observations. This novel platform could play a key role in defining our ultimate view of the polarized microwave sky.