thesan Reionization meets galaxy assembly Large-volume radiation-magneto-hydrodynamic simulations that capture the interplay between cosmic reionization and galaxy formation across a 300-million-light-year patch of the Universe.

Each snapshot provides a "picture" of the simulation at a given cosmic time. THESAN provides 80 of such snapshots. The scale factor and redshift at which they are produced are listed under Snapshot times below (click to open). Note: THESAN includes two DM-only runs that were run to …

Volume rendering of the HI fraction (left) and ionizing radiation field (right) in the Thesan-1 simulation. The top and bottom plots show the time evolution of these quantities, with the moving circle representing the time shown in the renderings.

The THESAN-ZOOM project is a suite of zoom-in cosmological radiation-hydrodynamic simulations exploring galaxy evolution during the first two billion years of the Universe. It builds on the THESAN project, named after the Etruscan goddess of dawn, symbolic of the cosmic dawn when hydrogen was reionized by the first stars and galaxies.

For select redshifts of \(z = \{6, 7, 8, 9, 10\}\) we produce galaxy spectral energy distribution (SED) catalogs for the flagship THESAN-1 simulation, directly mirroring the SUBFIND subhalo catalogs.

The primary science goals of THESAN are to investigate the connections between galaxies and the intergalactic medium throughout the Epoch of Reionization. The unique simulation approach invites progress and insights on a number of important open questions.

The LHaloTree merger tree is one large data structure split across several HDF5 files named trees_sf1_[NumLastSnapshot].[chunkNum].hdf5, where [chunkNum] goes from e.g. 0 to 1200 for Thesan-1.

THESAN provides one catalog for each snapshot. The scale factor and redshift at which they are produced are listed under Group catalogs times below (click to open). Group catalogs times

The THESAN-ZOOM project is a suite of zoom-in radiation hydrodynamic simulations that self-consistently model the formation of some of the first galaxies in the Universe across a broad mass range and follows them for 2 billion years (until redshift 3).

While running the THESAN simulations we output high time cadence Cartesian outputs of the full particle data onto a regular Cartesian grid using a first order Particle-In-Cell approach. THESAN-1 uses a 1024 3 grid while the medium resolution runs use 512 3 grids, setting the cell sizes to ∼93 and ∼186 ckpc, respectively.