Stellar Feedback in Dwarf Galaxy Formation

TL;DR

This paper demonstrates through high-resolution cosmological simulations that stellar feedback from supernovae and stellar winds can significantly alter the central density profiles of dwarf galaxies, aligning models with observations.

Contribution

It provides detailed simulations showing how stellar feedback causes gravitational potential fluctuations that reduce central dark matter density in dwarf galaxies.

Findings

Feedback induces large-scale gas motions.

Potential fluctuations lead to core formation.

Models match observed dwarf galaxy profiles.

Abstract

Dwarf galaxies pose significant challenges for cosmological models. In particular, current models predict a dark matter density that is divergent at the center, in sharp contrast with observations which indicate an approximately constant central density core. Energy feedback, from supernova explosions and stellar winds, has been proposed as a major factor shaping the evolution of dwarf galaxies. We present detailed cosmological simulations with sufficient resolution both to model the relevant physical processes and to directly assess the impact of stellar feedback on observable properties of dwarf galaxies. We show that feedback drives large-scale, bulk motion of the interstellar gas resulting in significant gravitational potential fluctuations and a consequent reduction in the central matter density, bringing the theoretical predictions in agreement with observations.