Constraints on Massive Axion-Like Particles from X-ray Observations of NGC1275

TL;DR

This paper uses X-ray observations of NGC1275 in the Perseus Cluster to set new constraints on massive axion-like particles by detecting their potential impact on the AGN's X-ray spectrum.

Contribution

It extends previous constraints on ALPs by analyzing the spectral modulations caused by photon-ALP conversion for masses up to 10^-11 eV.

Findings

Set new bounds on ALPs with masses up to 10^-11 eV

Demonstrated the effectiveness of X-ray spectral analysis for ALP constraints

Extended previous limits on massless ALPs to massive ALPs

Abstract

If axion-like particles (ALPs) exist, photons can convert to ALPs on passage through regions containing magnetic fields. The magnetised intracluster medium of large galaxy clusters provides a region that is highly efficient at ALP-photon conversion. X-ray observations of Active Galactic Nuclei (AGNs) located within galaxy clusters can be used to search for and constrain ALPs, as photon-ALP conversion would lead to energy-dependent quasi-sinusoidal modulations in the X-ray spectrum of an AGN. We use Chandra observations of the central AGN of the Perseus Cluster, NGC1275, to place bounds on massive ALPs up to m_a ~ 10^-11 eV, extending previous work that used this dataset to constrain massless ALPs.