Effects of SN Feedback on the Dark Matter Distribution

TL;DR

This study uses cosmological simulations to investigate how supernova feedback influences the dark matter distribution in galaxies, revealing that feedback effects are more pronounced in smaller galaxies and depend on various physical parameters.

Contribution

It is the first to systematically analyze the impact of SN feedback parameters on dark matter profiles in simulated Milky-Way type galaxies.

Findings

Dark matter distribution is affected by SN feedback through baryon redistribution.

Small galaxy halos are more sensitive to SN feedback effects.

Dark matter response depends on stellar mass, shape, and star formation burstiness.

Abstract

We use cosmological simulations to study the effects of supernova (SN) feedback on the dark matter distribution in galaxies. We simulate the formation of a Milky-Way type galaxy using a version of the SPH code GADGET2 which includes chemical enrichment and energy feedback by SN, a multiphase model for the gas component and metal-dependent cooling. We analyse the impact of the main three input SN feedback parameters on the amplitude and shape of the dark matter density profiles, focusing on the inner regions of the halo. In order to test the dependence of the results on the halo mass, we simulated a scale-down version of this system. First results of this ongoing work show that the dark matter distribution is affected by the feedback, through the redistribution of the baryons. Our findings suggest that the response of the dark matter halo could be the result of a combination of several physical parameters such as the amount of stellar mass formed at the centre, its shape, and probably the bursty characteristics of the star formation rate. As expected, we find that the dark matter haloes of small galaxies are more sensitive to SN feedback. Higher resolution simulations are being performed to test for numerical effects.