The EAGLE simulations of galaxy formation: Public release of particle data

This manual accompanies the release of the particle data for 24 simulations of the EAGLE suite of cosmological hydrodynamical simulations of galaxy formation by the virgo consortium. It describes how to download these snapshots and how to extract datasets from them, emphasising the meaning of variables, and their units. We provide examples for extracting the particle data in python. This data release complements our earlier release of numerous integrated properties of the galaxies in EAGLE through an SQL relational database. This database has been updated to include the additional simulations that are part of the present data release. Scientists wanting to use EAGLE may find it useful to first investigate whether their analysis can be performed using the database, before accessing the particle data. The particles in the snapshot files are indexed by a peano-hilbert key. This allows for an eased extraction of simply connected spatial volumes, without needing to read the entire snapshot. This makes it possible to analyse many aspects of galaxies using modest computing resources, even when using EAGLE simulations with large numbers of particles. A reading routine is provided to simplify this process.