The role of Stellar Feedback in the formation of galactic disks and bulges in a LCDM Universe

TL;DR

This paper investigates how stellar feedback influences galaxy formation, particularly in shaping galactic disks and bulges, using high-resolution cosmological simulations that resolve feedback effects without sub-grid assumptions.

Contribution

The study demonstrates that resolving stellar feedback at scales below 50 pc is crucial for accurately modeling its impact on galaxy structure in LCDM simulations.

Findings

High-resolution (better than 50 pc) simulations reproduce hot gas bubbles and chimneys.

Stellar feedback regulates bulge formation and inner rotation curves.

Runaway stars contribute significantly to feedback energy at resolved scales.

Abstract

Although supernova explosions and stellar winds happens at scales bellow 100 pc, they affect the interstellar medium(ISM) and galaxy formation. We use cosmological N-body+Hydrodynamics simulations of galaxy formation, as well as simulations of the ISM to study the effect of stellar feedback on galactic scales. Stellar feedback maintains gas with temperatures above a million degrees. This gas fills bubbles, super-bubbles and chimneys. Our model of feedback, in which 10%-30% of the feedback energy is coming from runaway stars, reproduces this hot gas only if the resolution is better than 50 pc. This is 10 times better than the typical resolution in cosmological simulations of galaxy formation. Only with this resolution, the effect of stellar feedback in galaxy formation is resolved without any assumption about sub-resolution physics. Stellar feedback can regulate the formation of bulges and can shape the inner parts of the rotation curve.