The effects of different Type Ia SN yields on Milky Way chemical evolution

TL;DR

This study investigates how different Type Ia supernova nucleosynthesis models influence the chemical evolution of the Milky Way, comparing model predictions with observational data to identify the most accurate progenitor scenarios.

Contribution

It systematically evaluates various Type Ia SN yield sets and combines progenitor models to improve the match with observed chemical abundance patterns in the Milky Way.

Findings

Classical W7 and WDD2 models produce similar Fe and alpha-element patterns to recent models.

Fe-peak element results depend on explosion mechanism and white dwarf initial conditions.

A combination of near- and sub-Chandrasekhar yields best reproduces observed element abundances.

Abstract

We study the effect of different Type Ia SN nucleosynthesis prescriptions on the Milky Way chemical evolution. To this aim, we run detailed one-infall and two-infall chemical evolution models, adopting a large compilation of yield sets corresponding to different white dwarf progenitors (near-Chandrasekar and sub-Chandrasekar) taken from the literature. We adopt a fixed delay time distribution function for Type Ia SNe , in order to avoid degeneracies in the analysis of the different nucleosynthesis channels. We also combine yields for different Type Ia SN progenitors in order to test the contribution to chemical evolution of different Type Ia SN channels. The results of the models are compared with recent LTE and NLTE observational data. We find that "classical" W7 and WDD2 models produce Fe masses and [$\alpha$/Fe] abundance patterns similar to more recent and physical near-Chandrasekar and sub- Chandrasekar models. For Fe-peak elements, we find that the results strongly depend either on the white dwarf explosion mechanism (deflagration-to-detonation, pure deflagration, double detonation) or on the initial white dwarf conditions (central density, explosion pattern). The comparison of chemical evolution model results with observations suggests that a combination of near-Chandrasekar and sub-Chandrasekar yields is necessary to reproduce the data of V, Cr, Mn and Ni, with different fractions depending on the adopted massive stars stellar yields. This comparison also suggests that NLTE and singly ionised abundances should be definitely preferred when dealing with most of Fe-peak elements at low metallicity.