# Common envelope to explosion delay time of type Ia supernovae

## TL;DR

This paper investigates the timing of type Ia supernovae after common envelope evolution, revealing a subset with very short delay times and suggesting different physical processes govern these early events compared to long-term delays.

## Contribution

It provides a new expression for the rate of short-delay type Ia supernovae and links these events to specific progenitor scenarios involving common envelope evolution.

## Key findings

- Short CEE to explosion delay (CEED) supernovae constitute ~0.1 of all SNe Ia.
- Proposes a different rate expression for SNe Ia with CEED<10^6 years.
- Indicates different physical processes may govern short and long delay times.

## Abstract

I study the rate of type Ia supernovae (SNe Ia) within about a million years after the assumed common envelope evolution (CEE) that forms the progenitors of these SNe Ia, and find that the population of SNe Ia with short CEE to explosion delay (CEED) time is ~fewx0.1 of all SNe Ia. I also claim for an expression for the rate of these SNe Ia that occur at short times after the CEE, t(CEED)<10^6 year, that is different from that of the delay time distribution (DTD) billions of years after star formation. This tentatively hints that the physical processes that determine the short CEED time distribution (CEEDTD) are different (at least to some extend) from those that determine the DTD at billions of years. To reach these conclusions I examine SNe Ia that interact with a circumstellar matter (CSM) within months after explosion, so called SNe Ia-CSM, and the rate of SNe Ia that on a time scale of tens to hundreds of years interact with a CSM that might have been a planetary nebula, so called SNe Ia inside a planetary nebula (SNIPs). I assume that the CSM in these populations results from a CEE, and hence this study is relevant mainly to the core degenerate (CD) scenario, to the double degenerate (DD) scenario, to the double detonation (DDet) scenario with white dwarf companions, and to the CEE-wind channel of the single degenerate (SD) scenario.