Simulated galaxies offer fresh evidence of dark matter

21 April 2017

A simulation of a galaxy, showing stars as blue, gas as red and dark matter as light grey

A simulated galaxy is pictured, showing the main ingredients that make up a galaxy: the stars (blue), the gas from which the stars are born (red), and the dark matter halo that surrounds the galaxy (light grey).
(Credit: A Benitez-Llambay and A Ludlow)

A UK research team funded by STFC have created a simulation which provides further evidence of the existence of dark matter.

Cosmologists at Durham University used sophisticated computer modelling techniques to simulate the formation of galaxies in the presence of dark matter – the substance which is believed to hold the universe together, but scientists are yet to prove its existence.

Using this simulation, the team were able to demonstrate that the size and rotation speed of the galaxies were linked to their brightness in a similar way to observations made by astronomers.

Until now, theories of dark matter have predicted a much more complex relationship between the size, mass and brightness of galaxies than is actually observed, which has led to dark matter sceptics proposing alternative theories that are seemingly a better fit with what we see.

The Durham team used powerful supercomputers to model the formation of galaxies of various sizes, compressing billions of years of evolution into a few weeks, in order to demonstrate that the existence of dark matter is consistent with the observed relationship between mass, size and luminosity of galaxies.

The research was led by Dr Aaron Ludlow of the Computational Cosmology department at Durham University, and he said: “This solves a long-standing problem that has troubled the dark matter model for over a decade. The dark matter hypothesis remains the main explanation for the source of the gravity that binds galaxies. Although the particles are difficult to detect, physicists must persevere.”

Read the news item from the Durham University website.

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