MaGICC Disks: Matching Observed Galaxy Relationships Over a Wide Stellar Mass Range

TL;DR

This study uses a physical simulation model to accurately reproduce a wide range of observed properties of disc galaxies, emphasizing the role of outflows in galaxy formation and evolution.

Contribution

It demonstrates that large-scale outflows are essential for matching observed galaxy relations across a broad stellar mass range, using a unified physical model.

Findings

Simulated galaxies match observed mass, luminosity, and rotation relations.

Outflows are crucial for reproducing galaxy surface brightness and rotation curves.

Model aligns with observations of circum-galactic media OVI absorption lines.

Abstract

We use the same physical model to simulate four galaxies that match the relation between stellar and total mass, over a mass range that includes the vast majority of disc galaxies. The resultant galaxies, part of the Making Galaxies in a Cosmological Context (MaGICC) program, also match observed relations between luminosity, rotation velocity, size, colour, star formation rate, HI mass, baryonic mass, and metallicity. Radiation from massive stars and supernova energy regulate star formation and drive outflows, balancing the complex interplay between cooling gas, star formation, large scale outflows, and recycling of gas in a manner which correctly scales with the mass of the galaxy. Outflows also play a key role in simulating galaxies with exponential surface brightness profiles, flat rotation curves and dark matter cores. Our study implies that large scale outflows are the primary driver of the dependence of disc galaxy properties on mass. We show that the amount of outflows invoked in our model is required to meet the constraints provided by observations of OVI absorption lines in the circum-galactic-media of local galaxies.