Integrated NIR-to-radio SED modelling of M 99 with HerBIE. Filled black circles show observed photometry used in the fit; grey diamonds indicate corresponding synthetic photometry. Left panel: Full SED fit (black line), including stellar emission (starBB, blue), dust emission using powerU with THEMIS (green), and radio continuum (radio, red). Right panel: Fit limited to λ ≥ 100 μm using a single-T MBB (MBB1, green), excluding stellar emission. Empty circles denote data not included in the fit. Residuals are shown below each panel.