The Impact of Feedback on Disk Galaxy Scaling Relations

TL;DR

This paper investigates how galactic outflows (feedback) influence key scaling relations in disk galaxies, demonstrating that models including outflows better match observations and can help distinguish different feedback mechanisms.

Contribution

The study shows that incorporating galactic outflows into disk formation models is essential to accurately reproduce observed galaxy scaling relations and differentiate feedback processes.

Findings

Models without outflows fail to match observed scaling relations.

Outflow models successfully reproduce observed relations.

Different outflow mechanisms predict distinguishable slopes.

Abstract

We use a disk formation model to study the effects of galactic outflows (a.k.a. feedback) on the rotation velocity - stellar mass - disk size, gas fraction - stellar mass, and gas phase metalicity - stellar mass scaling relations of disk galaxies. We show that models without outflows are unable to explain these scaling relations, having both the wrong slopes and normalization. The problem can be traced to the model galaxies having too many baryons. Models with outflows can solve this "over-cooling" problem by removing gas before it has time to turn into stars. Models with both momentum and energy driven winds can reproduce the observed scaling relations. However, these models predict different slopes which, with better observations, may be used to discriminate between these models.