# The Cosmic Foreground Explorer (COFE): A balloon-borne microwave polarimeter to characterize polarized foregrounds

## TL;DR

COFE is a balloon-borne microwave polarimeter designed to map polarized foregrounds across 80% of the sky at 10-20 GHz, aiding future CMB experiments in detecting primordial gravitational waves.

## Contribution

It introduces a new balloon-borne instrument capable of measuring polarized foregrounds over a large sky area with high sensitivity, crucial for CMB polarization studies.

## Key findings

- Coverage of up to 80% of the sky achieved
- Sensitivity per pixel better than 100 μK/deg^2 from 10-20 GHz
- Provides essential foreground characterization for future CMB experiments

## Abstract

The COsmic Foreground Explorer (COFE) is a balloon-borne microwave polarime- ter designed to measure the low-frequency and low-l characteristics of dominant diffuse polarized foregrounds. Short duration balloon flights from the Northern and Southern Hemispheres will allow the telescope to cover up to 80% of the sky with an expected sensitivity per pixel better than 100 $\mu K / deg^2$ from 10 GHz to 20 GHz. This is an important effort toward characterizing the polarized foregrounds for future CMB experiments, in particular the ones that aim to detect primordial gravity wave signatures in the CMB polarization angular power spectrum.