Bayesian hierarchical model used to constrain ALP parameters: m_a, g_aγ, g_ae. The model assumes that these global parameters are shared across all 18 sources and govern both ALP production in stellar interiors and their conversion to photons in the Galactic magnetic field. Each star contributes a predicted photon flux based on its luminosity, distance, and a shared ALP spectral shape. This flux was convolved with the instrument response to yield the expected counts that were compared to the observed data. A joint-likelihood analysis was performed across all sources using the 3ML framework to obtain constraints on the ALP parameter space.