Properties of galaxies reproduced by a hydrodynamic simulation

TL;DR

This paper presents a high-resolution hydrodynamic simulation of cosmic evolution that successfully reproduces the diversity of galaxy types and their distribution, matching observations across multiple scales.

Contribution

It introduces a simulation starting shortly after the Big Bang that models 13 billion years of evolution with unprecedented resolution and physical detail.

Findings

Reproduces a mixed population of elliptical and spiral galaxies.

Matches the distribution of galaxies in clusters.

Accurately models metal and hydrogen content in galaxies.

Abstract

Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies due to numerical inaccuracies and incomplete physical models. Moreover, because of computational constraints, they were unable to track the small scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a volume of $(106.5\,{\rm Mpc})^3$. It yields a reasonable population of ellipticals and spirals, reproduces the distribution of galaxies in clusters and statistics of hydrogen on large scales, and at the same time the metal and hydrogen content of galaxies on small scales.