My research initially focused on the study of massive stars and the progenitors of core-collapse supernovae. It has now broadened in all the possible implications of accounting for binary interactions when modelling stars and stellar populations. This is important because at least 50% of massive stars are in binaries. Binary interactions cause increased mass loss and mass transfer, and this gives rise to many different avenues for stellar evolution
To enable my research I have in collaboration with Assoc. Prof. Elizabeth Stanway I have to combine my stellar evolution models with libraries of synthetic atmosphere spectra to create a unique Binary Population and Spectral Synthesis code (BPASS, Eldridge & Stanway, 2009 & 2012; Eldridge, Stanway et al., 2017; Stanway & Eldridge, 2018; bpass.auckland.ac.nz). While similar codes (such as starburst99) exist BPASS has five important features, each of which set it apart from other codes and in combination make it the cutting edge. First, and most important, is the inclusion of binary evolution in modelling the stellar populations. The general effect of binaries is to cause a population of stars to look bluer at an older age than predicted by single-star models. Secondly, detailed stellar evolution models are used rather than an approximate rapid population synthesis method. Thirdly, I use only theoretical model spectra in my syntheses with as few empirical inputs as possible to create completely synthetic models to compare with observations. Fourthly, the code also predicts other observations such as rate of electromagnetic and gravitataional transients. Finally, we make results public and accessible to other researchers to enable everyone to include interacting binaries in their work.
Current research projects include:
- Understanding the stars and galaxies associated with gravitational wave events
- supernova lightCURVE POPulation Synthesis (CURVEPOPS)
- Investigating the diverse mix of type Ia supernovae
- The progenitors of type IIb, Ib and Ic supernovae