Clearing the Smoke: Nebular Spectra of 100+ Type Ia Supernovae Exclude Single Degenerate Progenitors

We place statistical constraints on Type Ia supernova (SN Ia) progenitors using 226 nebular phase spectra of 110 SNe Ia. We find no evidence of stripped companion emission in any of the nebular phase spectra. Upper limits are placed on the amount of mass that could go undetected in each spectrum using recent hydrodynamic simulations. With these null detections, we place an observational $3\sigma$ upper limit on the fraction of SNe Ia that are produced through the classical H-rich non-degenerate companion scenario of $ < 5.6\%$. Additionally, we set a tentative upper limit on He star progenitor scenarios of $< 6.5\%$, although further theoretical modelling is required. As part of our analysis, we also derive a Nebular Phase Phillips Relation, which approximates the brightness of a SN Ia in the nebular phase using the peak magnitude and decline rate parameter $\Delta m_{15} (B)$.