A new stellar population synthesis model library

Supervisors
Prof. Maurizio Salaris

One of the major open questions in modern astrophysics is the origin and evolution of galaxies. One way to address this problem is to study the star formation histories (SFHs) of galaxies of different types, which tells us the rate at which gas is transformed into stars and the evolution of its chemical composition.

The large majority of galaxies are so distant that we can observe only their integrated light, the sum of the light of all their stars, and the challenge is to decode the information on the SFH imprinted in this light.

Stellar population synthesis techniques do exactly this. Using stellar evolution model libraries and stellar spectra, we can calculate integrated magnitudes and spectra of distant galaxies, and develop methods to derive their SFHs.

The goal of this project is to build a new state-of-the-art stellar population synthesis library of integrated magnitudes and spectra of stellar populations, using a recently published new database of stellar models and isochrones (BaSTI-IAC -- Hidalgo et al. 2018, Pietrinferni et al. 2021). The project involves the identification of a suitable stellar spectral library to couple to the models, the extension of the stellar evolution models to the Asymptotic Giant Branch phase, calculations of integrated spectra and magnitudes of single-age, single-metallicity stellar populations, the development of a code that calculates integrated magnitudes and spectra for an arbitrary star formation history, and tests on available data.

The project, supervised by Prof. Maurizio Salaris, is in collaboration with scientists in Italy and Spain.

References:

Hidalgo, S. L. 2018, ApJ, 856, 125

Conroy, C. 2013,  Annu. Rev. Astron. Astrophys. 2013. 51, 393

Pietrinferni, A. et al, 2021, ApJ, 908, 102

galaxy spectra