Stellar Populations in type Ia supernova host galaxies at intermediate-high redshift: Star formation and metallicity enrichment histories

TL;DR

This study analyzes the star formation and metallicity histories of 680 galaxies hosting type Ia supernovae across a broad redshift range, revealing a significant correlation between supernova brightness residuals and stellar metallicity.

Contribution

It provides a comprehensive analysis of stellar populations in SN Ia host galaxies at intermediate-high redshift, using a large sample and improved metallicity measurements to understand supernova-host galaxy relations.

Findings

Hubble residuals depend on stellar metallicity with a slope of -0.061 mag/dex.

Sample includes 680 galaxies with redshift 0.04 to 1, analyzed via inverse stellar population synthesis.

Results support previous findings linking supernova brightness to host galaxy metallicity.

Abstract

We present a summary of our project that studies galaxies hosting type Ia supernova (SN Ia) at different redshifts. We present Gran Telescopio de Canarias (GTC) optical spectroscopy of six SN Ia host galaxies at redshift $z\sim 0.4-0.5$. They are joined to a set of SN Ia host galaxies at intermediate-high redshift, which include galaxies from surveys SDSS and COSMOS. The final sample, after a selection of galaxy spectra in terms of signal-to-noise and other characteristics, consists of 680 galaxies with redshift in the range $0.04 < z < 1$. We perform an inverse stellar population synthesis with the code {\sc fado} to estimate the star formation and enrichment histories of this set of galaxies, simultaneously obtaining their mean stellar age and metallicity and stellar mass. After analysing the correlations among these characteristics, we look for possible dependencies of the Hubble diagram residuals and supernova features (luminosity, color and strength parameter) on these stellar parameters. We find that the Hubble residuals show a clear dependence on the stellar metallicity weighted by mass with a slope of -0.061\,mag\,dex$^{-1}$, when represented in logarithmic scale, $\log{ \langle Z_{M}/Z_{\odot}\rangle }$. This result supports our previous findings obtained from gas oxygen abundances for local and SDSS-survey galaxies. Comparing with other works from the literature that also use the stellar metallicity, we find a similar value, but with more precision and a better significance (2.08 vs $\sim$ 1.1), due to the higher number of objects and wider range of redshift of our sample.