Many of the fundamental properties of galaxies are encoded in their spectral energy distributions (SEDs). In principle, one can extract a variety of galaxy properties, including the star formation history, chemical enrichment history, dust content, elemental abundance pattern, and stellar initial mass function (IMF) from SEDs. The method by which this information is extracted is known as stellar population synthesis (SPS). SPS models have been employed to estimate basic properties such as the star formation rate, metallicity, and total stellar mass. This project will use the next generation SPS model, extensively calibrated against data on individual stars and globular clusters, to make predictions for the full SED shape (as opposed to a limited number of narrow lines) as a function of individual abundance ratios, age, and the IMF.
The investigators will use this model to measure for the first time the detailed elemental abundance patterns and the low-mass IMF in early-type galaxies over a wide range in galaxy mass. These quantities will provide fundamental new insight into the formation and evolution of these complex stellar systems. One noteworthy example is the measurement of the abundances of s-process neutron capture elements, which is novel and will open up new areas of extragalactic research.
Educationally, this project will support a graduate student for three years to be trained in the development and use of the next generation of SPS models. The team will also write a pedagogical paper to explain in simple physical terms the trends observed in synthetic spectral libraries.
