Probing Axion–Photon Mixing with High-resolution X-Ray Spectroscopy
8 affiliations
- 1Chinese Academy of Sciences (NAOC)
- 2International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP, WPI)
- 3University of Chinese Academy of Sciences
- 4Tsinghua University
- 5Institute of Particle and Nuclear Studies (IPNS)
- 6Graduate University for Advanced Studies (SOKENDAI)
- 7The University of Tokyo Institutes for Advanced Study
- 8National Astronomical Observatory of Japan
Abstract
Axion-like particles (ALPs) provide a compelling avenue for exploring physics beyond the Standard Model. In astrophysical magnetized plasmas, an ALP–photon coupling g aγ induces energy-dependent oscillations in the photon survival probability that imprint modulations on emission spectra. X-ray observations of bright spectrally smooth sources can provide particularly sensitive probes of ultralight ALPs with masses m a ≲ 10 ⁻¹¹ eV due to long propagation distances, strong magnetic fields, and high photon statistics. We present a comprehensive forecast of ALP–photon conversion in three representative systems: (i) background active galactic nuclei (AGNs) observed through foreground intracluster magnetic fields, (ii) central AGNs within their host cluster halos, and (iii) Galactic X-ray binaries viewed through the Milky Way field. Using detailed simulations, we assess the prospective sensitivity of high-resolution X-ray missions including XRISM, Athena, and Arcus. For typical magnetic field configurations, a 320 ks XRISM observation or an 8 ks Athena observation of the Perseus Cluster AGN NGC 1275 can reach down to g aγ ∼ 5 × 10 ⁻¹³ GeV ⁻¹ at m a ≲ 10 ⁻¹² eV, surpassing the current best limit. We quantify the impact of magnetic field modeling, photon statistics, and spectral binning strategies. Our results demonstrate the scientific potential of future X-ray observatories to probe photon–ALP coupling in previously inaccessible parameter space, offering a powerful window into physics beyond the Standard Model.
Related
- Probing the Axion--Photon--Dark Photon Interaction with LHC Mono-Photons and Fermi-LAT Gamma-Ray Lines
- Bc meson spectroscopy from Bayesian MCMC: probing confinement and state mixing
- Phenomenology of axion-meson mixing and scattering processes
- Plasma instability splits axion-photon conversion lines
- Probing Neutrinophilic Axion-Like Particles in Tritium Beta Decay
BibTeX
@article{zhou2026probing,
title = {{Probing Axion–Photon Mixing with High-resolution X-Ray Spectroscopy}},
author = {Yu Zhou and Jiejia Liu and Volodymyr Takhistov and Kazuhisa Mitsuda},
journal = {The Astrophysical Journal},
year = {2026},
month = sep,
doi = {10.3847/1538-4357/ae9f5d},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/ae9f5d},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Probing Axion–Photon Mixing with High-resolution X-Ray Spectroscopy
AU - Yu Zhou
AU - Jiejia Liu
AU - Volodymyr Takhistov
AU - Kazuhisa Mitsuda
PY - 2026
DA - 2026/09/30
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/ae9f5d
UR - https://iopscience.iop.org/article/10.3847/1538-4357/ae9f5d
AB - Axion-like particles (ALPs) provide a compelling avenue for exploring physics beyond the Standard Model. In astrophysical magnetized plasmas, an ALP–photon coupling g aγ induces energy-dependent oscillations in the photon survival probability that imprint modulations on emission spectra. X-ray observations of bright spectrally smooth sources can provide particularly sensitive probes of ultralight ALPs with masses m a ≲ 10 ⁻¹¹ eV due to long propagation distances, strong magnetic fields, and high photon statistics. We present a comprehensive forecast of ALP–photon conversion in three representative systems: (i) background active galactic nuclei (AGNs) observed through foreground intracluster magnetic fields, (ii) central AGNs within their host cluster halos, and (iii) Galactic X-ray binaries viewed through the Milky Way field. Using detailed simulations, we assess the prospective sensitivity of high-resolution X-ray missions including XRISM, Athena, and Arcus. For typical magnetic field configurations, a 320 ks XRISM observation or an 8 ks Athena observation of the Perseus Cluster AGN NGC 1275 can reach down to g aγ ∼ 5 × 10 ⁻¹³ GeV ⁻¹ at m a ≲ 10 ⁻¹² eV, surpassing the current best limit. We quantify the impact of magnetic field modeling, photon statistics, and spectral binning strategies. Our results demonstrate the scientific potential of future X-ray observatories to probe photon–ALP coupling in previously inaccessible parameter space, offering a powerful window into physics beyond the Standard Model.
SN - 0004-637X
SN - 1538-4357
ER -