Properties of 145 SNe Ia

We analyse a representative sample of 145 nearby SNe Ia observed within +/-5d of B-band maximum light, including normal, 91T-, and 91bg-like events with measured light-curve decline rates ({Delta}m_15_) and SiII and CaII line properties from the literature.

We model PVF and HVF velocity distributions using Gaussian Mixture Models, compare SiII and CaII PVF velocity distributions, assess CaII HVF properties, and test correlations between SiII PVF velocities and {Delta}m_15_, with emphasis on HVF effects. For the first time, we show that the CaII PVF velocity distribution, measured for the same events at the same phases as SiII, is predominantly unimodal, in contrast to the well-known bimodal SiII PVF distribution that supports the high-velocity/normal-velocity division.