Diffsky
Diffsky synthetic galaxy catalogs built on Last Journey.
When to use: Synthetic galaxy samples with continuous redshift coverage for survey-like analyses.
Key facts
| Property | Value |
|---|---|
| Base simulation | Last Journey |
| Redshift range | 0.05 < z < 3.1 |
Access
Access requires membership in the OpenCosmoALCF Globus group.
Membership requests can be submitted from each group's page in the Globus Groups web interface.
About this dataset
The in-development Diffsky catalogs map Last Journey halo and core assembly histories to synthetic galaxy growth and spectral-energy-distribution-related properties. The modeling combines concepts developed in Diffmah and Diffstar so that galaxy histories remain connected to the full assembly histories of their associated structures.
The current portal query offers the Cosmos Survey and the SDSS FENIKS Survey calibrations over 0.05 < z < 3.1. Queries can filter by redshift and observed stellar mass, and can optionally include low-mass synthetic cores when they are available for the selected calibration.
OpenUniverse2024 used an earlier Diffsky prototype with the Outer Rim simulation. It is part of the model lineage, not a description of this Last Journey catalog.
Related publications
- OpenUniverse2024: A shared, simulated view of the sky for the next generation of cosmological surveys (arXiv)
- A Differentiable Model of the Assembly of Individual and Populations of Dark Matter Halos
- Diffstar: a fully parametric physical model for galaxy assembly history
- The Last Journey. I. An Extreme-scale Simulation on the Mira Supercomputer (arXiv)
- The Last Journey. II. SMACC—Subhalo Mass-loss Analysis Using Core Catalogs (arXiv)
- Modeling the Galaxy Distribution in Clusters using Halo Cores (arXiv)