2025/02/18 by Li, Jun, Bi, Xiao-Jun, Gao, Lin-Qing +1
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · doi:10.48550/arxiv.2502.12883
High energy photons traveling through astrophysical magnetic fields have the potential to undergo oscillations with axion-like particles (ALPs), resulting in modifications to the observed photon spectrum. High energy γ-ray sources with significant magnetic field strengths provide an ideal setting to investigate this phenomenon. Ton 599, a flat spectrum radio quasar with a magnetic field strength on the order of Gauss in its emission region, presents a promising opportunity for studying ALP-photon oscillations. In this study, we analyze the effects of ALP-photon oscillations on the γ-ray spectrum of Ton 599 as observed by Fermi-LAT. Our investigation considers the potential influences of the broad-line region and dusty torus on the γ-ray spectrum of Ton 599. We set the constraints on the ALP parameters at the 95% confidence level, and find that the constraints on \(gaγ\) can reach approximately \(2 × 10-12~GeV-1\) for \(ma ∼ 109~eV\).