Evidence for short-lived SN Ia progenitors

TL;DR

This study provides evidence for a short-lived progenitor channel of Type Ia supernovae with lifetimes under 180 million years, which could impact their use in cosmology due to potential systematic biases.

Contribution

It identifies a new short-lived progenitor population for Type Ia supernovae using spectral analysis, highlighting its importance for cosmological measurements.

Findings

Evidence for progenitors with <180 Myr lifetimes

Implications for supernova standardization in cosmology

Potential bias in high-redshift supernova surveys

Abstract

We use the VESPA algorithm and spectra from the Sloan Digital Sky Survey to investigate the star formation history of the host galaxies of 257 Type Ia supernovae. We find 5$\sigma$ evidence for a short-lived population of progenitors with lifetimes of less than 180 Myr, indicating a Type Ia supernova channel arising from stars in the mass range $\sim$3.5-8 $M_\odot$. As standardizeable candles, Type Ia supernovae play an important role in determining the expansion history of the Universe, but to be useful for future cosmological surveys, the peak luminosity needs to be free of uncorrected systematic effects at the level of 1-2%. If the different progenitor routes lead to supernovae with even moderately small differences in properties, then these need to be corrected for separately, or they could lead to a systematic bias in future supernovae surveys, as the prompt route is likely to increase in importance at high redshift. VESPA analysis of hosts could be a valuable tool in this, by identifying which progenitor route is most likely.