The Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic

TL;DR

ALBATROS is a new sub-Antarctic radio array designed to image low-frequency Galactic emission with significantly improved resolution, aiming to probe cosmic dark ages through 21-cm emission measurements despite observational challenges.

Contribution

The paper introduces ALBATROS, a novel array of autonomous antennas on Marion Island, enhancing low-frequency radio imaging resolution for cosmic studies.

Findings

Successful deployment of ALBATROS prototype stations.

Pathfinder observations demonstrating array capabilities.

Potential to improve understanding of cosmic dark ages.

Abstract

Measurements of redshifted 21-cm emission of neutral hydrogen at <30 MHz have the potential to probe the cosmic "dark ages," a period of the universe's history that remains unobserved to date. Observations at these frequencies are exceptionally challenging because of bright Galactic foregrounds, ionospheric contamination, and terrestrial radio-frequency interference. Very few sky maps exist at <30 MHz, and most have modest resolution. We introduce the Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic (ALBATROS), a new experiment that aims to image low-frequency Galactic emission with an order-of-magnitude improvement in resolution over existing data. The ALBATROS array will consist of antenna stations that operate autonomously, each recording baseband data that will be interferometrically combined offline. The array will be installed on Marion Island and will ultimately comprise 10 stations, with an operating frequency range of 1.2-125 MHz and maximum baseline lengths of ~20 km. We present the ALBATROS instrument design and discuss pathfinder observations that were taken from Marion Island during 2018-2019.