IllustrisTNG

IllustrisTNG
Name	IllustrisTNG
Developer	* Max Planck Institute for Astrophysics * MIT * Harvard–Smithsonian Center for Astrophysics * Princeton University * Columbia University
Initial release	2018
Genre	Cosmological simulation

IllustrisTNG is a suite of large cosmological magnetohydrodynamical simulations developed to study galaxy formation and large-scale structure across cosmic time. The project built on prior efforts to model baryonic processes and dark matter using high-performance computing facilities, producing outputs used by researchers in observational astronomy and theoretical astrophysics. The collaboration involved institutions and researchers associated with multiple survey teams and theoretical groups.

Overview

IllustrisTNG was conceived as a successor to earlier numerical programs and collaborations such as Illustris (simulation), Millennium Simulation, EAGLE (simulation), Bolshoi (simulation), and Horizon-AGN, aiming to improve treatments of feedback and magnetohydrodynamics. It targeted a broad mass range from dwarf galaxies relevant to Sloan Digital Sky Survey observations up to massive clusters comparable to those studied by Planck (spacecraft), Chandra X-ray Observatory, and Atacama Cosmology Telescope teams. The collaboration included contributors from institutions like University of California, Berkeley, Max-Planck-Institut für extraterrestrische Physik, University of Cambridge, Yale University, and Imperial College London, and interfaced with instrumentation groups from Very Large Telescope, Subaru (telescope), and Hubble Space Telescope programs. IllustrisTNG outputs addressed questions tied to surveys such as Dark Energy Survey, Kilo-Degree Survey, Hyper Suprime-Cam, and observatories including ALMA, VLA, and James Webb Space Telescope.

Simulation Design and Physics Models

The suite implemented physical modules to model radiative cooling, star formation, stellar evolution, chemical enrichment, supernova feedback, and active galactic nucleus (AGN) feedback, building on conceptual frameworks used by teams from Caltech, Stanford University, Cornell University, University of Chicago, and Johns Hopkins University. Magnetohydrodynamics (MHD) were included via algorithms similar to those used in studies affiliated with Princeton Plasma Physics Laboratory and Los Alamos National Laboratory, enabling comparison with theoretical predictions tied to Fermi Gamma-ray Space Telescope observations and IceCube neutrino constraints. The AGN feedback prescriptions were tuned to reproduce scaling relations known from Sloan Digital Sky Survey and Two Micron All Sky Survey results, and to match halo mass functions inferred by groups at Max Planck Institute for Astrophysics and Kavli Institute for Cosmology, Cambridge.

Numerical Methods and Code

IllustrisTNG used the moving-mesh code Arepo, developed by researchers associated with Heidelberg Institute for Theoretical Studies, Max Planck Institute for Astrophysics, and Technical University of Munich, incorporating Riemann solvers and constrained transport methods comparable to implementations from Los Alamos National Laboratory and Lawrence Berkeley National Laboratory. The code and simulation campaigns relied on leadership-class supercomputers including Blue Waters (supercomputer), Titan (supercomputer), DiRAC, and national facilities operated by NERSC and PRACE. Post-processing and halo finding employed tools such as friends-of-friends and SUBFIND akin to algorithms used by teams from University of Zurich and University of Washington, while mock-observation pipelines interfaced with instrument simulators from Space Telescope Science Institute and modeling groups at Carnegie Institution for Science.

Major Results and Scientific Impact

TNG produced measurable improvements in reproducing galaxy colors, sizes, and baryon fractions when compared with predecessors like Illustris (simulation), aligning better with observational results from COSMOS and CANDELS. The project influenced interpretations of galaxy quenching studied by researchers at Max Planck Institute for Astronomy, Royal Observatory Edinburgh, and Instituto de Astrofísica de Canarias, and provided simulated cluster pressure profiles comparable to analyses from Planck (spacecraft) and South Pole Telescope. TNG studies informed models of the circumgalactic medium explored by teams at University of California, Santa Cruz and University of Colorado Boulder, impacted theoretical work on angular momentum and morphology connected to studies from ETH Zurich and Leiden University, and shaped constraints on black hole growth discussed at Harvard University and Columbia University. The results have been cited in contexts ranging from reionization modeling relevant to LOFAR and SKA planning to chemical enrichment patterns compared with surveys by GALAH and APOGEE collaborators.

Data Release and Accessibility

The collaboration issued public data releases enabling access by researchers affiliated with institutions like Flatiron Institute, Center for Computational Astrophysics, University of Toronto, and McMaster University. Data portals provided halo catalogs, merger trees, synthetic images, and particle data used by observers from European Southern Observatory, National Radio Astronomy Observatory, and National Optical-Infrared Astronomy Research Laboratory. The releases facilitated cross-comparison with observational datasets from GALEX, WISE, Spitzer Space Telescope, and archival products maintained by Mikulski Archive for Space Telescopes.

Applications and Follow-up Studies

Follow-up work built on TNG outputs across many groups, leading to targeted studies by researchers at University of Michigan, University of Illinois Urbana-Champaign, University of California, San Diego, University of Pennsylvania, University of Oxford, University of Edinburgh, Stockholm University, University of Melbourne, and Monash University. Applications included mock survey generation for Euclid (spacecraft), covariance estimation for DESI, lensing predictions compared with CFHTLenS, and chemical evolution studies tied to Keck Observatory spectroscopy. Subsequent projects and successor simulations by labs at Max Planck Institute for Astrophysics, Harvard-Smithsonian Center for Astrophysics, and MIT continued to refine subgrid physics and resolution strategies informed by TNG findings.

Category:Cosmological simulations