SimulationCosmology · Universe

IllustrisTNG

The Next Generation of the Illustris simulations: a suite of large cosmological magnetohydrodynamic simulations that model how galaxies, gas, stars, black holes and magnetic fields evolve from shortly after the Big Bang to today.

Cosmological simulation · TNG50 / TNG100 / TNG300 · Arepo code

Type: Cosmological magnetohydrodynamic simulation
Volumes: TNG50 (~50 Mpc), TNG100 (~100 Mpc), TNG300 (~300 Mpc)
Code: Arepo moving-mesh hydrodynamics
Physics: Gravity, gas, magnetic fields, star formation, black-hole feedback, chemistry
First data release: TNG100 in 2018 · TNG50 and TNG300 in 2019
Purpose: Model galaxy formation across cosmic time
Collaboration: An international team of astrophysicists
Access: Free data and tools at tng-project.org

A virtual galaxy, grown from first principles

IllustrisTNG Collaboration

IllustrisTNG simulation showing dark matter and gas assembling into galaxies and the cosmic web — A volume from the IllustrisTNG simulation, showing dark matter and gas assembling into galaxies and the cosmic web. Image: IllustrisTNG Collaboration, CC BY-SA 4.0.

The next generation of Illustris

IllustrisTNG is the successor to the original Illustris simulation, rebuilt with updated physics. It adds magnetic fields, a more detailed treatment of supermassive-black-hole feedback, improved galactic winds, and new models for how chemical elements are spread through gas. The goal is a self-consistent universe where the galaxy population emerges from the same physical rules as the large-scale structure.

The name “TNG” stands for The Next Generation. Each run follows dark matter and gas from soon after the Big Bang to the present, so a single model can be compared against both the cosmic web and individual galaxies.

Three volumes, one physics

The project runs the same physics in three cubic volumes of increasing size and decreasing resolution, each suited to a different kind of question.

TNG50: the highest-resolution run, able to resolve the structure of individual galaxies and their inner gas.
TNG100: the intermediate run and the workhorse, balancing volume with galaxy-scale detail.
TNG300: the largest volume, designed for statistics on clusters, voids and large-scale structure.

What it models

Dark matter: the gravitational scaffolding that draws gas into haloes.
Gas and magnetic fields: magnetohydrodynamics on a moving mesh, rather than a fixed grid.
Star formation and feedback: gas cooling, star birth, supernova winds and chemical enrichment.
Black holes: supermassive black holes that grow and heat or eject surrounding gas, quenching star formation.

What it has shown

IllustrisTNG reproduces a wide range of observations: the split between blue, star-forming galaxies and red, quenched ones; the growth of supermassive black holes; the amplification of magnetic fields inside galaxies and clusters; and the way galaxies line up with the filaments of the cosmic web. Because the runs are public, astronomers around the world use them as a virtual sky to test theories against data.

Visit the IllustrisTNG project site to browse interactive visualizations, download data, and read the method papers.

Worth knowing

IllustrisTNG runs on the moving-mesh code Arepo, not a fixed grid.
TNG300 models a cube of the universe about 300 megaparsecs on a side.
The simulations are public, so any researcher can query them like a virtual telescope.