Webinaire ASNUM

Damien Chapon

CEA Saclay

The Galactica database: an open, generic and versatile tool for the dissemination

of numerical simulation data in astrophysics.

Résumé :

The Galactica simulation database is a platform designed to assist computational astrophysicists with their open science approach based on FAIR principles. It offers the means to publish their numerical simulation projects, whatever their field of application or research theme and provides access to reduced datasets and object catalogs online. The application implements the Simulation Datamodel IVOA standard. To give the scientific community the possibility to also access raw simulation data, Galactica integrates WebServices able to generate, on an “on-demand” basis, high-level data products that can be customized to meet specific user requirements. To that end, the Galactica central web application communicates with a high-scalability ecosystem of data-processing servers called ‘Terminus’ by means of an industry-proven asynchronous task management system. Each Terminus node, hosted in a research institute, a regional or national supercomputing facility, contributes to the ecosystem by providing both the storage and the computational resources required to store the massive simulation datasets and post-process them to create the data products requested on Galactica, hence guaranteeing fine-grained sovereignty over data and resources. This distributed architecture is very versatile, it can be interfaced with any kind of data-processing software, written in any language, handling raw data produced by every type of simulation code used in the field of computational astrophysics. Its genericity and versatility, together with its excellent scalability makes it a powerful tool for the scientific community to disseminate numerical models in astrophysics at the exascale era. To help computational astrophysicists publish their simulation projects online, a user-fiendly python API called ‘astrophysix’ has also been implemented and documented. With a few lines of Python that can be easily integrated into an existing a scientific analysis workflow, scientists can generate numerical study HDF5 files ready for upload on Galactica. With a single click, the entire project web pages can be deployed and accessible to the entire scientific community. Together, the astrophysix Python package, the Galactica web application and the Terminus post-processing server constitutes the three core components of the ‘Galactica software suite’ for Open Science in computational astrophysics.