Feedback effects of aspherical supernovae explosions on galaxies

TL;DR

This study uses a chemodynamical model to show that aspherical supernovae significantly affect star formation, chemical evolution, and gas dynamics in dwarf galaxies, leading to slower chemical enrichment and distinctive features.

Contribution

It introduces a new chemodynamical model comparing spherical and aspherical supernova feedback effects on galaxy evolution, highlighting the importance of supernova geometry.

Findings

A-SNe reduce star formation rates by a factor of ~3 compared to spherical SNe.

A-SNe lead to slower chemical evolution and unique abundance patterns.

A-SNe cause formation of gaseous holes and energetic outflows in dwarf galaxies.

Abstract

We investigate how explosions of aspherical supernovae (A-SNe) can influence star formation histories and chemical evolution of dwarf galaxies by using a new chemodynamical model. We mainly present the numerical results of two comparative models so that the A-SN feedback effects on galaxies can be more clearly seen. SNe originating from stars with masses larger than 30M_sun are A-SNe in the "ASN" model whereas all SNe are spherical ones (S-SNe) in the "SSN" model. Each S-SN and A-SN are assumed to release feedback energy of 10^{51} erg and 10^{52} erg, respectively, and chemical yields and feedback energy of A-SN ejecta depend on angles between the axis of symmetry and the ejection directions. We find that star formation can become at least by a factor of ~3 lower in the ASN model in comparison with the SSN one owing to the more energetic feedback of A-SNe. As a result of this, chemical evolution can proceed very slowly in the ASN model. A-SN feedback effects can play a significant role in the formation of giant gaseous holes and energetic gaseous outflow and unique chemical abundances (e.g., high [Mg/Ca]). Based on these results, we provide a number of implications of the A-SN feedback effects on galaxy formation and evolution.