OpenCosmo Compute Portal Documentation

The OpenCosmo Compute Portal provides access to large cosmological simulations run by the Cosmological Physics and Advanced Computing (CPAC) group at Argonne National Laboratory. Portal tasks run at the computing facilities where the data resides and return results that you can download and analyze locally.

Getting Started

• Submitting Tasks: Learn how to run portal tasks from the web interface, the ocp command line, or an MCP-enabled assistant.

• Supporting Libraries: Install the ocp CLI and the OpenCosmo Python Toolkit.

• Datasets: Browse the simulations and data products available on the portal.

• Available Queries: Review the query and analysis tasks currently available on the portal.

• Reading Returned Data: Open downloaded result files and continue analysis with the OpenCosmo Python Toolkit.

• Glossary: Definitions of common terms used throughout the portal and documentation.

Available Tasks

The portal currently provides the following tasks. See the Available Queries page for full descriptions, supported simulations, and required inputs.

Gravity-Only Simulation Queries

Gravity-only data products comprise dark matter halo catalogs with associated radial profiles and, for high-mass clusters, member particles. The available queries reduce these catalogs, in individual snapshots or on the lightcone, to the halos of interest and return the associated data.

Full-sky lightcone maps in HEALPix format, suitable for weak-lensing and related analyses, are also available. The map query returns maps over a chosen redshift range at a selectable output resolution.

• Halo Lightcone Query (Gravity-Only)
• Halo Query (Gravity-Only)
• Halo-Particles Query (Gravity)
• Map Query (Gravity-Only)

Hydrodynamic Simulation Queries

Hydrodynamic simulation data includes halos, galaxies, and the dark matter, gas, star, and black hole particles associated with them. The available queries filter halo and galaxy catalogs and retrieve particle data from simulation snapshots and lightcones.

• Galaxy Query
• Halo Lightcone Query (Hydro)
• Halo Query (Hydro)
• Halo-Particles Query (Hydro)

Synthetic Galaxy Catalog Queries

Synthetic galaxy catalog data currently consists of in-development Diffsky mocks generated from Last Journey halo mass-assembly histories. The available query filters catalogs by redshift and galaxy properties and returns the selected galaxies.

• Diffsky Synthetic Galaxy Query

Visualization

Visualization tasks select simulation structures and generate ready-to-view scientific previews alongside reusable query outputs.

• Visualize Halo

Prepackaged Analysis

The portal provides a number of prepackaged analysis modules from the HAvoCC framework (HACC Analysis and Validation to Observational Constraints Code) that run with customizable parameters. Each module produces a figure, in many cases with comparisons to published simulation and observational results, and in most cases the plotted values can also be returned as tabulated data. Details of each analysis (mass bins, axis ranges, etc.) are set through parameters in the input form. A finished analysis provides a downloadable zip archive containing the plots and tabulated data.

• Black Hole Mass - Stellar Mass Relation
• Cluster Profiles
• Concentration-Mass Relation
• Galaxy Stellar Mass Function
• Halo Mass Function
• M500 Mass Scalings
• Stellar Mass - Halo Mass Relation
• X-ray - M500 Scalings
• YSZ - M500 Scalings

Data Format

Query results are returned as HDF5 files that the OpenCosmo Python Toolkit can read and manipulate without requiring knowledge of how the data is stored. Prepackaged analysis tasks instead return a zip archive of plots and tabulated data, and visualization tasks produce image previews alongside a Parquet file.