Distances with <4% Precision from Type Ia Supernovae in Young Star-Forming Environments

TL;DR

This study demonstrates that Type Ia supernovae in young, star-forming environments can be used as highly precise distance indicators, achieving less than 4% uncertainty in distance measurements.

Contribution

The paper introduces a method to calibrate Type Ia supernovae in star-forming regions with <4% distance precision, highlighting the role of progenitor age in luminosity variations.

Findings

Calibration accuracy of ~0.07 magnitudes (~4% distance)

Supernovae in star-forming environments show tight luminosity scatter

Progenitor age dispersion primarily drives light-curve and luminosity relations

Abstract

The luminosities of Type Ia supernovae (SNe), the thermonuclear explosions of white-dwarf stars, vary systematically with their intrinsic color and the rate at which they fade. From images taken with the Galaxy Evolution Explorer (GALEX), we identified SNe Ia that erupted in environments that have high ultraviolet surface brightness and star-formation surface density. When we apply a steep model extinction law, we calibrate these SNe using their broadband optical light curves to within ~0.065 to 0.075 magnitudes, corresponding to <4% in distance. The tight scatter, probably arising from a small dispersion among progenitor ages, suggests that variation in only one progenitor property primarily accounts for the relationship between their light-curve widths, colors, and luminosities.