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

We describe our project to study galaxies hosting type Ia supernova (SN Ia) at different redshifts. We present optical spectroscopy of 6 galaxies at redshift $z \sim 0.45$ observed with Gran Telescopio de Canarias. They are joined to a set of SN Ia host galaxies at intermediate-high redshift, taken from SDSS and COSMOS surveys. After some selection cuts, in terms of signal-to-noise and other criteria, our final sample consists of 680 galaxies in the range $0.04 < z < 1$ of redshift. We perform an inverse stellar population synthesis with the code FADO to estimate the star formation histories. We simultaneously obtain their stellar mass, and their mean stellar age and metallicity. We then look for possible correlations of the Hubble diagram residuals and of the supernova light curve features (luminosity, color and strength) on these stellar parameters. We find that the Hubble diagram residuals show a correlation with the weighted by mass stellar metallicity (in logarithmic scale) with a slope of -0.061 mag dex$^{-1}$. This result supports our previous findings obtained with gas oxygen abundances for local and SDSS galaxies. This is also similar to the value found in other works from the literature. Our result is in agreement with others, but it is obtained with more precision and a better significance due to the higher number of objects and wider range of redshift of our sample.