The Illustris project was a series of astrophysical

simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...

s run by an international collaboration of scientists. The aim was to study the processes of

galaxy formation and evolution The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have ge ...

in the

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...

with a comprehensive physical model. Early results were described in a number of publications following widespread press coverage. The project publicly released all data produced by the simulations in April, 2015. A follow-up to the project, IllustrisTNG, was presented in 2017.

Illustris simulation

Overview

The original ''Illustris project'' was carried out by Mark Vogelsberger and collaborators as the first large-scale galaxy formation application of Volker Springel's novel Arepo code. The ''Illustris project'' included large-scale

cosmological Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...

simulations A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the s ...

of the evolution of the universe, spanning initial conditions of the

Big Bang The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

, to the present day, 13.8 billion years later. Modeling, based on the most precise data and calculations currently available, are compared to actual findings of the

observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these obj ...

in order to better understand the nature of the

, including

galaxy formation The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have ge ...

dark matter Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ab ...

and

dark energy In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. The first observational evidence for its existence came from measurements of supernovas, which showed that the univer ...

. The simulation included many physical processes which are thought to be critical for galaxy formation. These include the formation of stars and the subsequent "feedback" due to supernova explosions, as well as the formation of super-massive black holes, their consumption of nearby gas, and their multiple modes of energetic feedback. Images, videos, and other data visualizations for public distribution are available a
official media page

Computational aspects

The main ''Illustris'' simulation was run on the Curie supercomputer at CEA (France) and the SuperMUC supercomputer at the Leibniz Computing Centre (Germany). A total of 19 million CPU hours was required, using 8,192 CPU cores. The peak memory usage was approximately 25 TB of RAM. A total of 136 snapshots were saved over the course of the simulation, totaling over 230 TB cumulative data volume. A code called "Arepo" was used to run the Illustris simulations. It was written by Volker Springel, the same author as the

GADGET A gadget is a mechanical device or any ingenious article. Gadgets are sometimes referred to as '' gizmos''. History The etymology of the word is disputed. The word first appears as reference to an 18th-century tool in glassmaking that was develo ...

code. The name is derived from the

Sator Square The Sator Square (or the Rotas-Sator Square, or the Templar Magic Square) is a two-dimensional acrostic class of word square containing a five-word Latin palindrome. The earliest Sator squares were found at several Roman-era sites, all in ROT ...

. This code solves the coupled equations of

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

and

hydrodynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and ...

using a

discretization In applied mathematics, discretization is the process of transferring continuous functions, models, variables, and equations into discrete counterparts. This process is usually carried out as a first step toward making them suitable for numerical ...

of space based on a moving

Voronoi tessellation Voronoi or Voronoy is a Slavic masculine surname; its feminine counterpart is Voronaya. It may refer to *Georgy Voronoy (1868–1908), Russian and Ukrainian mathematician **Voronoi diagram **Weighted Voronoi diagram ** Voronoi deformation density ** ...

. It is optimized for running on large, distributed memory supercomputers using an MPI approach.

Public data release

In April, 2015 (eleven months after the first papers were published) the project team publicly released all data products from all simulations. All original data files can be directly downloaded through th
data release webpage
This includes group catalogs of individual halos and subhalos, merger trees tracking these objects through time, full snapshot particle data at 135 distinct time points, and various supplementary data catalogs. In addition to direct data download, a web-based API allows for many common search and

data extraction Data extraction is the act or process of retrieving data out of (usually unstructured or poorly structured) data sources for further data processing or data storage (data migration). The import into the intermediate extracting system is thus usual ...

tasks to be completed without needing access to the full data sets.

German postage stamp

In December 2018, the Illustris simulation was recognized by

Deutsche Post The Deutsche Post AG, operating under the trade name Deutsche Post DHL Group, is a German multinational package delivery and supply chain management company headquartered in Bonn, Germany. It is one of the world's largest courier companies. T ...

through a special series

stamp Stamp or Stamps or Stamping may refer to: Official documents and related impressions * Postage stamp, used to indicate prepayment of fees for public mail * Ration stamp, indicating the right to rationed goods * Revenue stamp, used on documents to ...

IllustrisTNG

Overview

Th
IllustrisTNG project
"the next generation" follow up to the original Illustris simulation, was first presented in July, 2017. A team of scientists from Germany and the U.S. led by Prof. Volker Springel. First, a new physical model was developed, which among other features included

Magnetohydrodynamics Magnetohydrodynamics (MHD; also called magneto-fluid dynamics or hydromagnetics) is the study of the magnetic properties and behaviour of electrically conducting fluids. Examples of such magnetofluids include plasmas, liquid metals, ...

planned three simulations, which used different volumes at different resolutions. The intermediate simulation (TNG100) was equivalent to the original Illustris simulation. Unlike Illustris, it was run on the Hazel Hen machine at the

High Performance Computing Center, Stuttgart The High Performance Computing Center (HLRS) in Stuttgart, Germany, is a research institute and a supercomputer center. HLRS has currently a flagship installation of a HPE Apollo 9000 system called ''Hawk'' 26 PFLOPS peak performance replac ...

in Germany. Up to 25,000 computer cores were employed.

Public data release

In December 2018 the simulation data from IllustrisTNG was released publicly. The data service includes a JupyterLab interface.

Gallery

References

External links

*
Press release
- Center for Astrophysics Harvard & Smithsonian (7 May 2014). *
Illustris-Project
(6 May 2014). * -

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

(14 July 2014) * - article containing a comparison table of different simulation projects {{Portal bar, Astronomy, Physics, Space Astrophysics Cosmological simulation Physical cosmology

Illustris simulation

Overview

Computational aspects

Public data release

German postage stamp

IllustrisTNG

Overview

Public data release

Gallery

See also

References

External links