# Using large spectroscopic surveys to test the double degenerate model for Type Ia supernovae

## TL;DR

This paper proposes a method using existing spectroscopic survey data to efficiently identify white dwarf binaries that could be progenitors of Type Ia supernovae, significantly reducing observational effort.

## Contribution

It introduces a pre-selection technique based on radial velocity data from public surveys, enhancing the efficiency of detecting potential Type Ia progenitors among white dwarfs.

## Key findings

- Method reduces required observing time by tenfold.
- Doubles the size of the largest survey in less than 15% of the time.
- Discovered 7 new binary systems, confirming the method's effectiveness.

## Abstract

An observational constraint on the contribution of double degenerates to Type Ia supernovae requires multiple radial velocity measurements of ideally thousands of white dwarfs. This is because only a small fraction of the double degenerate population is massive enough, with orbital periods short enough, to be considered viable Type Ia progenitors. We show how the radial velocity information available from public surveys such as the Sloan Digital Sky Survey can be used to pre-select targets for variability, leading to a ten-fold reduction in observing time required compared to an unranked or random survey. We carry out Monte Carlo simulations to quantify the detection probability of various types of binaries in the survey and show that this method, even in the most pessimistic case, doubles the survey size of the largest survey to date (the SPY survey) in less than 15 per cent of the required observing time. Our initial follow-up observations corroborate the method, yielding 15 binaries so far (eight known and seven new), as well as orbital periods for four of the new binaries.