Simple Stellar Population Template Repository

FSPS (Flexible Stellar Population Synthesis)

FSPS templates generated using the FSPS code (Conroy et al. 2009, Conroy & Gunn 2010) via the python-fsps interface. These templates were retrieved using the retrieve_ssp_data_from_fsps function in DSPS, providing consistent formatting and wavelength coverage.

Available combinations include MIST, BASTI, Padova, and PARSEC isochrones with MILES, BaSeL, and C3K stellar spectral libraries, using Salpeter, Chabrier, and Kroupa IMFs. Solar metallicity normalized metalicity values can be inconsistent for different isochrone sets due to the different solar metallicity values assumed. Solar metallicities for MIST, BASTI, Padova, and PARSEC are 0.0142, 0.0200, 0.0190, and 0.0152, respectively. Refer to the FSPS manual for further details.

ProGeny

ProGeny is a new stellar population library software package that provides flexible generation of simple stellar populations (Robotham & Bellstedt 2024, Bellstedt & Robotham 2025). The fiducial ProGeny SSPs use MIST isochrones with various stellar spectral libraries including C3K, PHOENIX, and Allard. Please refer to the original paper for details. The ProGeny SSPs were downloaded from tinyurl.com/prospect-speclib/ and reformatted by Suchetha Cooray.

BPASS (Binary Population and Spectral Synthesis)

BPASS templates incorporate binary stellar evolution models, providing more realistic population synthesis by accounting for binary interactions Eldridge et al. 2017 (Stanway & Eldridge 2018). These templates are particularly important for understanding massive star populations and their spectral signatures. Please refer to the original paper for details. Downloaded from ProGeny compilation and reformatted.

The BPASS models are based on custom stellar evolution code that carefully accounts for mass and angular momentum transfer in binary systems. Binary interactions can significantly affect the spectral properties of stellar populations, especially in the UV regime where mass transfer can produce hot, luminous stars.

BC03 (Bruzual & Charlot 2003)

BC03 templates are from the widely-used Bruzual & Charlot stellar population synthesis models (Bruzual & Charlot 2003). These models use Padova isochrones and STELIB stellar spectral library, representing one of the most extensively tested and calibrated SSP sets in the literature. BC03 models include explicit treatment of planetary nebulae and have been benchmarked against numerous observational datasets. Downloaded from ProGeny compilation and reformatted.