CosmicWeb-21cm array: A New Radio Observation Array Design for 21cm Cosmology

TL;DR

The CosmicWeb-21cm array is a novel radio interferometer designed with innovative geometry, adaptive sampling, and machine learning processing to improve 21cm cosmology observations, enabling detailed mapping of the early universe.

Contribution

It introduces a co-designed array architecture, adaptive frequency sampling, and a machine-learning pipeline, advancing 21cm cosmology observation capabilities.

Findings

Achieves 99.7% foreground removal efficiency

Low noise temperature (<35 K) across 50-250 MHz

Enables high sensitivity mapping of the Epoch of Reionization

Abstract

This paper presents the CosmicWeb-21cm array, a novel radio interferometer designed to overcome the key challenges in 21 cm cosmology. Its core innovations include: (1) a multi-scale nested geometry combining a hexagonal core with logarithmic spiral arms for excellent UV coverage and calibration robustness; (2) an intelligent non-uniform frequency sampling strategy that adapts resolution to foreground and signal characteristics, reducing data volume while preserving information; and (3) a machine-learning-enhanced, physics-informed processing pipeline that achieves 99.7\% foreground removal efficiency; (4) a dual-polarization crossed dipole integrated with a dielectric lens and cryogenically cooled LNA, achieving stable beam patterns and low noise temperature ($<35$ K) across 50-250 MHz. These co-designed advances enable high sensitivity mapping of the Epoch of Reionization, dark energy constraints and cosmic-web structure.