Top: emergent luminosity in the Hα region and multiple epochs for model DDC15 with M_st of 0.0018, 0.017, and 0.18 M_⊙ from left to right. The color coding indicates epochs 100, 150, 200, 250, and 300 d after explosion (time increases from the upper curve to the lower curve; see also left panel of Fig. 2). Bottom: same as top, but we now subtract the luminosity arising from the model with M_st = 10⁻⁵ M_⊙, which has the effect of erasing the luminosity contribution from the metal-rich, SN Ia ejecta. The stripped material contributes not just through Hα emission, but also weak emission from other lines (e.g., Fe II) and some weak background continuum.