Updated bounds on Axion-Like Particle Dark Matter with the optical MUSE-Faint survey

TL;DR

This paper establishes new, more robust bounds on axion-like particle dark matter in the 2.65-5.27 eV mass range by analyzing MUSE observations of dwarf galaxies, improving previous constraints.

Contribution

It provides updated and stronger bounds on ALP-photon coupling using optical spectroscopic data, enhancing the robustness of previous limits in this mass range.

Findings

Bounds are the strongest within the 2.65-5.27 eV range.

Analysis of MUSE data constrains ALP decay signals.

Results improve upon previous bounds in robustness.

Abstract

Bounds are derived on the axion-like particle (ALP) to two-photon coupling in the mass range $2.65-5.27$ eV. The bounds are obtained by searching for the signal from ALP decay in the Multi Unit Spectroscopic Explorer (MUSE) observations of five dwarf spheroidal galaxies, under the assumption that ALPs constitute the dark matter component of the haloes. These bounds are of the same order and improve on the robustness of those of Reference~\cite{Regis}, and currently represent the strongest bounds within the considered mass range.