BFORE: The B-mode Foreground Experiment

TL;DR

BFORE is a proposed NASA balloon experiment focusing on dust foreground characterization at multiple frequencies to improve CMB B-mode polarization measurements and enable diverse astrophysical studies.

Contribution

It introduces a novel balloon-based survey with specific frequency bands, high resolution, and large sky coverage to advance CMB and Galactic science.

Findings

Design of a compact off-axis telescope with 10,000+ detectors

Projected to survey 1/4 of the sky with high resolution

Expected to improve constraints on inflation and Galactic magnetic fields

Abstract

The B-mode Foreground Experiment (BFORE) is a proposed NASA balloon project designed to make optimal use of the sub-orbital platform by concentrating on three dust foreground bands (270, 350, and 600 GHz) that complement ground-based cosmic microwave background (CMB) programs. BFORE will survey ~1/4 of the sky with 1.7 - 3.7 arcminute resolution, enabling precise characterization of the Galactic dust that now limits constraints on inflation from CMB B-mode polarization measurements. In addition, BFORE's combination of frequency coverage, large survey area, and angular resolution enables science far beyond the critical goal of measuring foregrounds. BFORE will constrain the velocities of thousands of galaxy clusters, provide a new window on the cosmic infrared background, and probe magnetic fields in the interstellar medium. We review the BFORE science case, timeline, and instrument design, which is based on a compact off-axis telescope coupled to >10,000 superconducting detectors.