diffstar

Code documentation can be found at diffstar.readthedocs.io.

Installation

The latest release of diffstar is available for installation with either pip or conda-forge:

$ conda install -c conda-forge diffstar

Alternatively, to install diffstar into your environment from the source code:

$ cd /path/to/root/diffstar
$ pip install .

Environment configuration

For a typical development environment with conda-forge:

$ conda create -c conda-forge -n diffit python=3.11 numpy numba flake8 pytest jax ipython jupyter matplotlib scipy h5py diffmah diffstar

Project data

Data for this project can be found at this URL.

Scripts and demo notebooks

The demo_diffstar_sfh.ipynb notebook in the docs folder illustrates how to use the Diffstar model for individual SFH, and how to generate the SFH of a population of galaxies using DiffstarPop.

The demo_diffmahpop_diffstarpop_sfh.ipynb notebook illustrates how to generate a subhalo catalog, and how to generate SFHs for each halo using parameters that reproduce UniverseMachine, IllustrisTNG or Galacticus.

See diffstar_fitting_script_umachine_mgash.py for an example of how to fit the SFHs of a large number of simulated galaxies in parallel with mpi4py.

The diffstar_fitter_demo.ipynb notebook demonstrates how to fit the SFH of a simulated galaxy with a diffstar approximation.

See fit_mstar_ssfr_pdfs_mgash.py for an example of how to use DiffstarPop to fit a set of Mstar and sSFR PDFs, and measure_smhm_smdpl_script_mpi_mgash.py for an example of how to generate the target data from a set of Diffstar fits.

Citing diffstar

The Diffstar paper has been published in Monthly Notices of the Royal Astronomical Society. Citation information for the paper can be found at this ADS link, copied below for convenience:

@ARTICLE{2023MNRAS.518..562A,
       author = {{Alarcon}, Alex and {Hearin}, Andrew P. and {Becker}, Matthew R. and {Chaves-Montero}, Jon{\'a}s},
        title = "{Diffstar: a fully parametric physical model for galaxy assembly history}",
      journal = {MNRAS},
     keywords = {galaxies: evolution, galaxies: fundamental parameters, galaxies: star formation, Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
         year = 2023,
        month = jan,
       volume = {518},
       number = {1},
        pages = {562-584},
          doi = {10.1093/mnras/stac3118},
archivePrefix = {arXiv},
       eprint = {2205.04273},
 primaryClass = {astro-ph.GA},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2023MNRAS.518..562A},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}