The Last Journey is a large-volume, gravity-only, cosmological N-body simulation evolving more than 1.24 trillion particles in a periodic box with a side-length of 5.025Gpc. It was implemented using the HACC simulation and analysis framework on the BG/Q system, Mira. The cosmological parameters are chosen to be consistent with the results from the Planck satellite. A range of analysis tools have been run in situ to enable a diverse set of science projects, and at the same time, to keep the resulting data amount manageable. Analysis outputs have been generated starting at redshift z~10 to allow for construction of synthetic galaxy catalogs using a semi-analytic modeling approach in post-processing. As part of our in situ analysis pipeline we employ a new method for tracking halo sub-structures, introducing the concept of subhalo cores. The production of multi-wavelength synthetic sky maps is facilitated by generating particle lightcones in situ, also beginning at z~10. We provide an overview of the simulation set-up and the generated data products; a first set of analysis results is presented. A subset of the data is publicly available.
@article{arxiv.2006.01697,
title = {The Last Journey. I. An Extreme-Scale Simulation on the Mira Supercomputer},
author = {Katrin Heitmann and Nicholas Frontiere and Esteban Rangel and Patricia Larsen and Adrian Pope and Imran Sultan and Thomas Uram and Salman Habib and Hal Finkel and Danila Korytov and Eve Kovacs and Silvio Rizzi and Joe Insley},
journal= {arXiv preprint arXiv:2006.01697},
year = {2021}
}
Comments
14 pages, 9 figures. Accepted for publication in ApJS. New visualization and new results for the matter correlation function added, minor edits. The Last Journey data products can be accessed here: https://cosmology.alcf.anl.gov/