The research group that gave us the most detailed time-lapse simulation of the universe’s evolution in 2014, spanning 13.8 billion years of cosmic evolution, is back in the spotlight with an even more advanced cosmological model that is providing new insights into how black holes influence the distribution of dark matter, how heavy elements are produced and distributed, and where magnetic fields originate.
Like the original Illustris project, Illustris: The Next Generation (IllustrisTNG for short) follows the progression of a cube-shaped universe from just after the Big Bang to the present day using the power of supercomputing. New physics and other refinements have been added to the original model and the scope of the simulated universe has been expanded to 1 billion light-years per side (from 350 million light-years per side previously). The first results from the project have been published in three separate articles in the journal Monthly Notices of the Royal Astronomical Society (Vol. 475, Issue 1).
A press release put out by the Max Planck Institute for Astrophysics, one of the partners, highlights the significance:
At its intersection points, the cosmic web of gas and dark matter predicted by IllustrisTNG contains galaxies quite similar to the shape and size of real galaxies. For the first time, hydrodynamical simulations could directly compute the detailed clustering pattern of galaxies in space. Comparison with observational data—including newest large surveys—demonstrate the high degree of realism of IllustrisTNG. In addition, the simulations predict how the cosmic web changes over time, in particular in relation to the underlying “back bone” of the dark matter cosmos.
“It is particularly fascinating that we can accurately predict the influence of supermassive black holes on the distribution of matter out to large scales,” said principal investigator Prof. Volker Springel of the Heidelberg Institute for Theoretical Studies. “This is crucial for reliably interpreting forthcoming cosmological measurements.”
The team also includes researchers from the Max Planck Institutes for Astronomy (MPIA, Heidelberg) and Astrophysics (MPA, Garching), Harvard University, the Massachusetts Institute of Technology (MIT) and the Flatiron Institute’s Center for Computational Astrophysics (CCA).
To capture the small-scale turbulent physics at the heart of galaxy formation, astrophysicists used a powerful version of the highly parallel moving mesh code, AREPO, which they deployed on Germany’s fastest supercomputer, Hazel Hen. Ancillary and test runs of the project were also run on the Stampede supercomputer at the Texas Advanced Computing Center, at the Hydra and Draco supercomputers at the Max Planck Computing and Data Facility, and on MIT/Harvard computing resources.
As detailed on the project website, IllustrisTNG actually consists of 18 simulations in total at varying scales. The largest (the highest-resolution TNG300 simulation) occupied 2,000 of Hazel Hen’s Xeons for just over two months. The simulations together generated more than 500 terabytes of data and will keep the team busy for years to come.
A visualization from the project shows the formation of a massive “late-type,” star-forming disk galaxy.