lightning.py

Note

The only stellar population models included in this distribution are the "legacy" PEGASE models used in IDL Lightning. The BPASS + Cloudy models produced by the BPASS collaboration and the recently developed BPASS + Cloudy and PEGASE + Cloudy models used in Lehmer+(2024) must be downloaded and placed in the appropriate model directories before they can be used with Lightning.

lightning.py is the python version of the Lightning SED-fitting code. The goal of the project is to maintain Lightning's primary design philosophy of simplicity and physically-based models, while taking advantage of Python's object-oriented nature and the wide array of pre-existing astronomical Python code to improve modularity and user-friendliness.

The IDL version of Lightning is now considered the "legacy" version, and will not see further development. Its documentation will remain available at lightning-sed.readthedocs.io, and the source code can still be downloaded from github.com/rafaeleufrasio/lightning.

This new python version contains all the features of IDL Lightning with the current notable exception of the Doore et al. (2021) inclination-dependent attenuation model. Users interested in the properties of highly-inclined disk galaxies are encouraged to continue to use IDL Lightning for their analyses, and to let the authors know if it would be nice to access that model through lightning.py.

Installation

Currently, lightning.py is not available on PyPI or conda-forge. Until it is uploaded, lightning.py and its dependencies can be installed by cloning the repo, creating a conda environment with the required dependencies, and then installing the package:

git clone https://github.com/ebmonson/lightningpy.git
cd lightningpy
conda env create -f environment.yml
conda activate lightning
pip install .  --no-deps

Model files will then need to be downloaded and dropped in the appropriate directories of the installed package. If you're following the instructions above, the root directory for the models will be

path/to/conda/envs/lightning/lib/python3.XX/site-packages/lightning/data/models/

where 3.XX should be replaced with the version of python used by your environment. You can locate your lightning install by opening a python terminal and doing

>>> import lightning
>>> print(lightning.__file__)

which will show you the root of the lightning install.

Documentation

Online documentation for the package can be found on its readthedocs page, and a compiled PDF version of the documentation is available in this repository.

License

lightning.py is available under the terms of the MIT license.

Citation

A paper describing lightning.py in application is forthcoming by Monson et al.; this page will be updated on submission.

In the meantime, work using the new PEGASE+Cloudy and BPASS+Cloudy models are encouraged to also cite Lehmer et al. (2024, in press at ApJS):

@ARTICLE{2024arXiv241019901L,
    author = {{Lehmer}, Bret D. and {Monson}, Erik B. and {Eufrasio}, Rafael T. and {Amiri}, Amirnezam and {Doore}, Keith and {Basu-Zych}, Antara and {Garofali}, Kristen and {Oskinova}, Lidia and {Andrews}, Jeff J. and {Antoniou}, Vallia and {Geda}, Robel and {Greene}, Jenny E. and {Kovlakas}, Konstantinos and {Lazzarini}, Margaret and {Richardson}, Chris T.},
    title = "{An Empirical Framework Characterizing the Metallicity and Star-Formation History Dependence of X-ray Binary Population Formation and Emission in Galaxies}",
    journal = {arXiv e-prints},
    keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena},
    year = 2024,
    month = oct,
    eid = {arXiv:2410.19901},
    pages = {arXiv:2410.19901},
    archivePrefix = {arXiv},
    eprint = {2410.19901},
    primaryClass = {astro-ph.GA},
    adsurl = {https://ui.adsabs.harvard.edu/abs/2024arXiv241019901L},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

Work using models described in the IDL Lightning implementation paper, Doore et al. (2023), should also cite that paper:

@ARTICLE{2023ApJS..266...39D,
    author = {{Doore}, Keith and {Monson}, Erik B. and {Eufrasio}, Rafael T. and {Lehmer}, Bret D. and {Garofali}, Kristen and {Basu-Zych}, Antara},
    title = "{Lightning: An X-Ray to Submillimeter Galaxy SED-fitting Code with Physically Motivated Stellar, Dust, and AGN Models}",
    journal = {\apjs},
    keywords = {Extragalactic astronomy, Galaxy properties, Star formation, Spectral energy distribution, 506, 615, 1569, 2129, Astrophysics - Astrophysics of Galaxies},
    year = 2023,
    month = jun,
    volume = {266},
    number = {2},
    eid = {39},
    pages = {39},
    doi = {10.3847/1538-4365/accc29},
    archivePrefix = {arXiv},
    eprint = {2304.06753},
    primaryClass = {astro-ph.GA},
    adsurl = {https://ui.adsabs.harvard.edu/abs/2023ApJS..266...39D},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}