BAORadio : Cartographie 3D de la distribution de gaz H$_I$ dans l'Univers

TL;DR

This paper proposes a novel 3D mapping method using 21 cm radio emission to study large-scale cosmic structures and dark energy, employing intensity mapping with a wide-band, multi-beam radio instrument.

Contribution

It introduces a new intensity mapping approach for 3D cosmic mapping that does not require detecting individual galaxies, enabling efficient large-scale structure studies.

Findings

Suitable for measuring BAO scale up to z~3

Requires a wide band, 100 MHz+ with multiple beams

Can be implemented with dense interferometric arrays or phased arrays

Abstract

3D mapping of matter distribution in the universe through the 21 cm radio emission of atomic hydrogen is a complementary approach to optical surveys for the study of the Large Scale Structures, in particular for measuring the BAO (Baryon Acoustic Oscillation) scale up to redshifts z <~ 3 and constrain dark energy. We propose to carry such a survey through a novel method, called intensity mapping, without detecting individual galaxies radio emission. This method requires a wide band instrument, 100 MHz or larger, and multiple beams, while a rather modest angular resolution of 10 arcmin would be sufficient. The instrument would have a few thousand square meters of collecting area and few hundreds of simultaneous beams. These constraints could be fulfilled with a dense array of receivers in interferometric mode, or a phased array at the focal plane of a large antenna.