A framework for controlled simulations of idealized galaxies
About
Nexus is an integral framework to create and evolve synthetic galaxies made of collisionless and gaseous components. It has been developed in response to the need for realistic, dynamically self-consistent, evolving galaxy models that avoid the complexity of full, and zoom-in, cosmological simulations. Nexus leverages the power of two publicly available, tried-and-tested astrophysical packages: the stellar-dynamics, action-based library Action-based Galaxy Modelling Architecture (AGAMA); and the adaptive mesh refinement, N-body/hydrodynamical code Ramses, modified to meet our needs. The latter incorporates a proprietary module to account for galaxy formation physics, including gas cooling and heating, star formation, stellar feedback, and chemical enrichment. The framework's basic functionality consists in the generation of bespoke initial conditions (ICs) for a diversity of galaxy models, which are advanced in time to simulate the galaxy’s evolution. The fully self-consistent ICs are generated with a distribution-function-based approach, as implemented in the galaxy modelling module of AGAMA – up to now restricted to collisionless components, extended in our framework to treat two types of gaseous configurations: hot haloes and gas discs.
The simulation output is processed (analysed/visualized)
with our custom Python package, the Ramses Analysis and Visualization Environment (RAVE), built around the Python astrophysical package Pynbody and the Python
interface to the Tcl/Tk graphical user interface toolkit TkInter.
A full description of Nexus, including validation tests, can be found in Tepper-García et al. (2024).
Core Team
- Thor Tepper-García (U Sydney)
- Joss Bland-Hawthorn (U Sydney)
- Eugene Vasiliev (U Surrey)
- Oscar Agertz (U Lund)
- Romain Teyssier (Princeton)
- Christoph Federrath (ANU)