A group of theoretical astrophysicists based in Germany has produced the largest and most detailed model of the distribution of visible matter in the universe. In doing so, they ran the most sophisticated simulation of the universe ever produced.
In science, the most successful theories are those that can explain what we have observed as well as predicting new and interesting phenomena. In astronomy, this is not easily achieved. We only have one universe to look at, and both testing and predictions are affected by this limitation. This is why astronomers often use simulations to compare current hypotheses to what we actually observe in the universe.
The Magneticum Pathfinder simulation is the latest of these models and represents a huge step forward, creating a sophisticated replica of the universe made of 180 billion elements. The full simulation generated 320 Terabytes of scientific data.
The simulation uses the three main ingredients of the universe: visible matter, dark matter and dark energy. Dark matter is a type of matter that cannot be seen; it doesn't emit or absorb light, though it has mass and so interacts with gravity. It is responsible for over one-quarter of the entire mass-energy content of the universe. Dark Energy, sometimes called vacuum energy, is responsible for the accelerated expansion of the universe.
Using these ingredients and detailed descriptions of many different physical processes, the simulation allows for the closest comparison between observations and theoretical models. The simulation was able to match the distribution of visible matter in the universe today, and it also discovered that dark matter halos – thought to envelop galaxies – spin around significantly faster around galaxies than cold gas does.
Technological advancements in astronomy, the availability of hundreds of Earth-based and space telescopes covering all wavelengths, and citizen scientists helping with the classification of galaxies has generated a wealth of observational knowledge. The Magneticum Pathfinder simulation, being so detailed, is the perfect instrument to compare the observations with the latest theories: It will allow for tweaks to the models and maybe predict some yet to be witnessed phenomena.
"Astronomical surveys from space telescopes like Planck or Hubble observe a large segment of the visible universe while sophisticated simulations so far could only model very small parts of the universe, making a direct comparison virtually impossible," said Klaus Dolag, leader of the project, in a statement. "Thus, Magneticum Pathfinder marks the beginning of a new era in computer-based cosmology."
The data produced is now available for interested researchers worldwide, and more information is available at the Magneticum Pathfinder website.