Synthesizer

Synthesizer is a Python package for generating synthetic astrophysical observables. It is modular, flexible, extensible and fast.

Read the documentation here.

Getting Started

The latest stable release of Synthesizer can be installed directly using pip,

pip install cosmos-synthesizer

Please refer to the installation documentation for further information.

Note: We do not currently support Windows, to use Synthesizer on Windows please install the Windows Subsystem for Linux (WSL).

Various configuration options can also be set at installation (see here).

Getting Grids

In most use cases you will need a grid of theoretical spectra. Browse premade grids in the Syndex catalogue, then download one with synthesizer-download --dataset <name>.

Note that you can also create your own grids using (or adapting) the syncretize repo.

Contributing

Please see here for contribution guidelines.

Citation & Acknowledgement

Please cite both of the following papers (Lovell et al. 2025, Roper et al. 2026) if you use Synthesizer in your research:

@article{Lovell2025Synthesizer,
    author = {Lovell, Christopher C. and Roper, William J. and Vijayan, Aswin P. and Wilkins, Stephen M. and Newman, Sophie and Seeyave, Louise},
    journal = {The Open Journal of Astrophysics},
    doi = {10.33232/001c.145766},
    year = {2025},
    month = {oct 9},
    publisher = {Maynooth Academic Publishing},
    title = {Synthesizer: a {Software} {Package} for {Synthetic} {Astronomical} {Observables}},
    volume = {8},
}

@article{Roper2026Synthesizer,
    author = {Roper, Will J. and Lovell, Christopher C. and Vijayan, Aswin and Wilkins, Stephen and Akins, Hollis and Berger, Sabrina and Sant Fournier, Connor and Harvey, Thomas and Iyer, Kartheik and Leonardi, Marco and Newman, Sophie and Pautasso, Borja and Perry, Ashley and Seeyave, Louise and Sommovigo, Laura and Punyasheel, Paurush and d'Hautefort, Adrien Aufan Stoffels and Rawlings, Alex},
    journal = {Journal of Open Source Software},
    doi = {10.21105/joss.09436},
    year = {2026},
    publisher = {Open Journals},
    title = {Synthesizer: Synthetic Observables for Modern Astronomy},
    volume = {11},
    number = {119},
    pages = {9436},
}

If you use any of the pre-built grids from the Syndex database please cite the grids release paper (Vijayan et al. 2026) and any other applicable citations as listed on Syndex:

@article{Vijayan2026Synthesizer,
   author = {{Vijayan}, Aswin P. and {Wilkins}, Stephen M. and {Newman}, Sophie L. and {Lovell}, Christopher C. and {Roper}, William J. and {Berger}, Sabrina and {Harvey}, Thomas and {Turner}, Jack C.},
   journal = {arXiv e-prints},
   doi = {10.48550/arXiv.2607.27467},
   year = 2026,
   title = "{Stellar photoionisation modelling in SYNTHESIZER}",
   archivePrefix = {arXiv},
   eprint = {2607.27467},
   primaryClass = {astro-ph.GA},
}

Licence

GNU General Public License v3.0