Linking Type Ia Supernova Progenitors and their Resulting Explosions
  Comparing the ejecta velocities at maximum brightness and narrow
circumstellar/interstellar Na D absorption line profiles of a sample of 23 Type
Ia supernovae (SNe Ia), we determine that the properties of SN Ia progenitor
systems and explosions are intimately connected. As demonstrated by Sternberg
et al. (2011), half of all SNe Ia with detectable Na D absorption at the
host-galaxy redshift in high-resolution spectroscopy have Na D line profiles
with significant blueshifted absorption relative to the strongest absorption
component, which indicates that a large fraction of SN Ia progenitor systems
have strong outflows. In this study, we find that SNe Ia with blueshifted
circumstellar/interstellar absorption systematically have higher ejecta
velocities and redder colors at maximum brightness relative to the rest of the
SN Ia population. This result is robust at a 98.9-99.8% confidence level,
providing the first link between the progenitor systems and properties of the
explosion. This finding is further evidence that the outflow scenario is the
correct interpretation of the blueshifted Na D absorption, adding additional
confirmation that some SNe Ia are produced from a single-degenerate progenitor
channel. An additional implication is that either SN Ia progenitor systems have
highly asymmetric outflows that are also aligned with the SN explosion or SNe
Ia come from a variety of progenitor systems where SNe Ia from systems with
strong outflows tend to have more kinetic energy per unit mass than those from
systems with weak or no outflows.
