In low-frequency radio observations and microwave foreground analysis (e.g., Planck, WMAP), the free-free emission (thermal bremsstrahlung) from ionized gas in the Galaxy often shows discrepancies between the expected optical depth derived from H$\alpha$ emission (corrected for dust) and the actual radio brightness temperature. Specifically, the inferred electron temperature $T_e$ required to match the radio data is sometimes unphysically high or shows a gradient with latitude that standard photo-ionization models cannot fully explain. Additionally, the "anomalous" component (AME) can be confused with free-free emission, leading to degeneracies in component separation that leave residuals in the CMB maps (Dickinson et al. 2003; Planck Collaboration 2016).