ASVO-TAO status: v2.0 deployed in September 2015 at Theoretical Astrophysical Observatory.

The Theoretical Astrophysical Observatory (TAO) houses queryable data from multiple popular cosmological simulations (currently the Millennium Simulation and Bolshoi Simulation, others coming) and galaxy formation models (currently Croton et al. 2006 (SAGE) and Benson 2010 (Galacticus), others coming) in a database that is optimised for rapid access. Query results can be funnelled through additional "modules" (described below) and sent to a local supercomputer for further processing and manipulation. All this is accessible via the cloud through a browser for access anywhere in the world by the astronomical community. TAO was developed, and is hosted and operated, by Swinburne University.

In September, TAO v.20 was deployed, with a number of significant enhancements and new features, including:

  • Premade catalogues: These are catalogues that have, for example, already been fashioned into a light-cone (e.g. for a particular survey), or have had their galaxy magnitudes already made, and hence do not need the TAOmodules to perform these tasks. Premade catalogues can be downloaded as-is after choosing your properties of interest, selection cuts, and output format.
  • Image module: This has been rebuilt, bigger and better! You’ll find a new UI for generating images which hopefully will make the process faster and more intuitive.
  • The SAGE model will have its public release (including paper) soon (https://github.com/darrencroton/sage). We’ll be updating the SAGE galaxy data to reflect this official version.

There will be an even more substantial release coming soon, which will include a significant update to the overall user interface, add an interactive image module workflow, and make available a new set of data import tools (for getting your simulations/models into TAO).

Please visit the Theoretical Astrophysical Observatory.

Core Features

Web interface: The interface is clean and intuitive to use. We avoid the need to have the user program SQL queries by providing a custom "point and click" interface to select galaxies and their properties, which auto-generates the query code in the background. The web interface allows users to easily pipe data through modules (described below) to produce enhanced data products for their science.

User accounts: An account system provides data security and allows us to manage each users usage of the available HPC resources. Users are provided with a place to store queried data for online access and as a temporary location for data that requires additional later processing (via modules).

Core Data Access: The core engine of TAO linksthe web interface and user account to the SQL database, modules, and HPC resources needed to process and manage the data for the user.


Light-Cone Module: This module re-maps the geometry of the simulated data cube on to the observer cone. Cone parameters are configurable and popular survey geometries will be available as presets.

  • Science: Mock light-cones are commonly used in survey science to test for systematics and biases in the data, as well as to explore science questions of interest in a more realistic setting. TAO enables users to generate identically produced cones that are sourced from different simulations and models, something that has never been done before.

Spectral Energy Distribution (SED) Module: This module takes the simulated data and offers a choice of different popular SED models to apply in post-processing. The SED Module is required by the Light-Cone Module to produce apparent magnitudes, but can be independently applied to any data in the theory observatory (e.g. the original data cube).

  • Science: SED post-processing vastly expands the wavelength coverage of all simulated galaxy data in the database regardless of its original state. This opens up TAO to a wide range of the community, from radio to optical to IR. It additionally provides a way to compare the predictions of different SED models and explore the theoretical uncertainty between them.

Mock Image Generation Module: This module takes the output of both the Light- Cone Module and SED Module and produces user defined mock images. Image parameters are configurable (e.g. area on the sky, depth, filter).

  • Mock images can be used to test source finding algorithms and to test the accuracy of galaxy environment measurements (to name but two examples).

Telescope Simulator Module: This module extends the functionality of the Light-Cone and SED Modules. It further filters the mock data to more closely mimic that expected from a particular telescope, for example by adding instrument noise. We have initially focused on a number of popular telescopes available to Australian astronomers, and more will be added in the future.

  • Science: By itself the Telescope Simulator Module can be used to generate different mock realisations of a proposed galaxy survey performed with a particular telescope. Combined with the Mock Image Generation Module, a user can simulate the expected imaging one would expect the telescope to produce.

TAO is configured so that additional modules can be built and easily inserted into the data chain as needs require in the future (e.g. a module to perform lensing on the simulated data).

Transformational Science:

Numerical astrophysics is emerging as an integral component of upcoming next generation survey programs, and the simulations generated as part of these programs will need a home. The Theoretical Astrophysical Observatory provides this home.

It is "light-weight" and "sleek", yet powerful and accessible.
It provides a platform to promote Australian simulations and models internationally.
It provides tools that multiply the value of existing theory data many-fold.


The TAO project team combines expertise in N-body and hydrodynamic simulations with all varieties of galaxy formation modelling in a high performance computing environment.

The project enables investigation into a wide range of interesting astrophysical phenomena, including (1) cosmology, dark matter and dark energy, (2) galaxy assembly, evolution and interactions, (3) supermassive black holes and quasars, and (4) large-scale structure, voids and environmental effects.

Open Source

TAO is an open source project with a GPL v3 license.  The code is available from: https://github.com/IntersectAustralia/asvo-tao

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