Constraints on axion-like particles from non-observation of spectral modulations for X-ray point sources

Journal article

We extend previous searches for X-ray spectral modulations induced by ALP-photon conversion to a variety of new sources, all consisting of quasars or AGNs located in or behind galaxy clusters. We consider a total of seven new sources, with data drawn from the Chandra archive. In all cases the spectrum is well fit by an absorbed power-law with no evidence for spectral modulations, allowing constraints to be placed on the ALP-photon coupling parameter $g_{a\gamma\gamma}$. Two sources are particularly good: the Seyfert galaxy 2E3140 in A1795 and the AGN NGC3862 within the cluster A1367, leading to 95\% bounds for light ALPs ($m_a \lesssim 10^{-12} {\rm eV}$) of $g_{a\gamma\gamma} \lesssim 1.5 \times 10^{-12} {\rm GeV}^{-1}$ and $g_{a\gamma\gamma} \lesssim 2.4 \times 10^{-12} {\rm GeV}^{-1}$ respectively.

Authors: Conlon, J; Day, F; Jennings, N; Krippendorf, S; Rummel, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Journal of Cosmology and Astroparticle Physics
• Volume: 2017
• Issue: 07
• Article number: 005
• Publication date: 2017-07-03
• Acceptance date: 2017-06-19
• DOI: 10.1088/1475-7516/2017/07/005
• EISSN: 1475-7516
• Keywords: active galactic nuclei; axions