The Formation of Galaxy Disks

TL;DR

This paper presents advanced SPH simulations of galaxy formation, demonstrating the importance of feedback and resolution in producing realistic disk galaxies with properties matching observations.

Contribution

It introduces high-resolution cosmological simulations that incorporate feedback and resolution effects to better replicate observed galaxy disk properties.

Findings

Simulated galaxies have flatter rotation curves.

Disks exhibit larger scale lengths.

Bulge-to-disk ratios are reduced.

Abstract

We present a new set of multi-million particle SPH simulations of the formation of disk dominated galaxies in a cosmological context. Some of these galaxies are higher resolution versions of the models already described in Governato et al (2007). To correctly compare simulations with observations we create artificial images of our simulations and from them measure photometric Bulge to Disk (B/D) ratios and disk scale lengths. We show how feedback and high force and mass resolution are necessary ingredients to form galaxies that have flatter rotation curves, larger I band disk scale lengths and smaller B/D ratios. A new simulated disk galaxy has an I-band disk scale length of 9.2 kpc and a B/D flux ratio of 0.64 (face on, dust reddened).