Delay Time Distribution of Type Ia Supernovae

We use a population number synthesis evolution code to compute the expected time distributions of type Ia supernova explosions, both through the single degenerate (a white dwarf accreting matter from a late main sequence or red giant companion) and double degenerate (the merger of two white dwarfs) scenario. The code has been updated to include the mass stripping effect in determining the type Ia supernova progenitors in the single degenerate scenario. The code also allows to differentiate between the alpha (based on the balance of energy) and gamma (based on the balance of angular momentum) scenario describing the energy conversion during common envelope evolution of binaries. The results of this Brussels code can be directly compared to those obtained by other evolution codes. Those agree that type Ia supernovae occur in a wide time range after star formation and that the shape and extent of this delay time distribution critically depends on whether the single or double degenerate scenario is used. The results predicted by the evolution code are then compared to the latest observed distributions. This allows to draw conclusions on the constraints put on the theoretical models by these observations. We conclude that the double degenerate scenario is dominant during most of the time after starburst, and that most of these events are created through a normal Roche lobe overflow evolution followed by spiral-in, not through a double common envelope phase.