Data access

All raw data and many data products from the THESAN simulation suite are publicly available at this page through the Globus application. You can also follow a step-by-step tutorial.

Available data

Most THESAN data are similar in format to those from the IllustrisTNG simulations. Some novel data output and products have unique formats. Both are described below.

The raw output from a single THESAN simulation are listed here. You can get more information by clicking on the name of each entry.

  • Snapshots : the full simulation output at 80 different cosmic times, between z=50 and z=5.5 (produced approximately every 10 Myr).
  • Group catalogs : the properties of haloes and galaxies in the simulation, at 80 different cosmic times.
  • Cartesian outputs : gas properties sampled on a Cartesian grid at high time cadence.

In addition to the raw data, we provide a number of data products, produced by post processing the THESAN data. The available data products are listed here. You can get more information by clicking on the name of each entry.

  • simulation.hdf5 file : file linking datasets across output chunks, automating the loading process.
  • eor.txt file : file with runtime global IGM properties.
  • Merger trees : evolutionary tracks of galaxies in the simulation and their properties.
  • Offset files : utility files that make easy to connect snapshot, groups and merger trees.
  • Hashtables : utility files that make easy to load particles based on their spatial position.
  • Cross-match files : utility files that make easy to find analog haloes across the different THESAN simulations.
  • Lyman-alpha catalogs : intrinsic Lyman-α properties of galaxies in the simulation.
  • Lines of sight : collection of gas properties extracted along random lines of sight through the simulation.
  • Filament catalogs : the filaments identified in the simulation and their properties.
  • Escape fraction catalogs: the escape fraction properties of galaxies in the simulation.
  • Galaxy SED catalogs : the spectral energy distributions of simulated galaxies, obtained in post-processing from the star and dust distributions.

Not all data are available for all THESAN simulations because of physical or numerical limitations. The table below shows which data are available for each run.


Following is a list of changes and addition to the data since they were first released, in reversed chronological order.

  • 02/08/2023 - Renamed ThesanHR directories and placed in the main Thesan directory
  • 30/07/2023 - New filaments catalogs! Files organised into subdirectories in the filaments directory.

General information about THESAN

Simulation discretize the different components of the Universe (like dark matter, stars, etc.) into resolution elements. In THESAN, there are four types of resolution elements, namely:
Type Component
0 Gas
1 Dark matter
4 Stars and wind particles
5 Black holes
Dark matter and stars are discretized into particles corresponding to a group of them of a given mass. Black holes are also represented by particles, but each one of them correspond to an individual black hole.
Gas is discretized using a Voronoi tessellation. Its resolution elements can be treated as particles, but are of different nature within the simulation.

Each resolution element has a number of parameters associated, describing physical or numerical properties. The parameters associated depend on its type (PartType) and are described in the page dedicated to snapshots.

Citation policy

To properly acknowledge the contributions of all individuals involved in the development of the THESAN simulation suite, its data products, and its data release, we kindly request that any publication using data or data products from the THESAN suite cites the three introductory papers and the data release paper. When data from the THESAN-HR suite are used, we ask that the corresponding paper is cited as well. These papers are: Furthermore, many of the data products have been described in additional papers, as outlined in the corresponding documentation page and in the data release paper. We request that these papers are also cited whenever the specific data described within it are used.