2018MNRAS.473.4932C

Galaxy clusters represent excellent laboratories to search for axion-like particles (ALPs). They contain magnetic fields which can induce quasi-sinusoidal oscillations in the X-ray spectra of active galactic nuclei situated in or behind them. Due to its excellent energy resolution, the X-ray Integral Field Unit instrument on board the Athena X-ray Observatory will be far more sensitive to ALP-induced modulations than current detectors. As a first analysis of the sensitivity of Athena to the ALP-photon coupling g_aγγ, we simulate observations of the Seyfert galaxy NGC 1275 (hosting the radio source 3C 84) in the Perseus cluster using the SIXTE simulation software. We estimate that for a 200 ks exposure, a non-observation of spectral modulations will constrain g_aγγ <= 1.5 x 10^- 13^GeV- 1^ for m_a <= 10^- 12^eV, representing an order of magnitude improvement over constraints derived using the current generation of satellites.