FEADME: Fast Elliptical Accretion Disk Modeling Engine

Abstract

We present FEADME (Fast Elliptical Accretion Disk Modeling Engine), a GPU-accelerated Python framework for modeling broad Balmer-line emission using a relativistic elliptical accretion-disk formalism. Leveraging JAX and NumPyro for differentiable forward modeling and efficient Bayesian inference, FEADME enables large-sample, reproducible analyses of disk-dominated emission-line profiles. We apply the framework to 237 double-peaked emitters (DPEs) from the literature and to five tidal disruption events (TDEs) with disk-like H$\alpha$ emission, fitting three physically motivated model families per spectrum and selecting the preferred model using the widely applicable information criterion (WAIC). After posterior-quality filtering, the disk-bearing active galactic nuclei (AGN) analysis sample contains 165 sources and the TDE sample contains 27 usable epochs. We find that AGN occupy a broad, continuous distribution of disk geometries and kinematics that is usefully summarized by five phenomenological Gaussian-mixture morphology bins. The TDE disk parameters overlap substantially with the AGN population in radial scale, local broadening, and emissivity slope, but TDEs are systematically less eccentric and show broader non-disk Gaussian components. The majority of both AGN and TDEs favor models that include both a disk and an additional broad-line component, suggesting that disk emission commonly coexists with more isotropic or wind-driven gas. These results indicate that once a line-emitting disk forms, its spectroscopic appearance is governed by similar physical processes in both persistent AGN and transient TDE accretion flows, and they demonstrate the utility of FEADME for population-level studies of disk structure in galactic nuclei.