FNWI --- IMAPP Department of Astrophysics
Radboud University > Faculty of Science > Department of Astrophysics

Steven C. Williams Astrophysics Research Institute Liverpool John Moores University, Liverpool, United Kingdom

Extragalactic Novae and Their Progenitors

Abstract: I will present the results of a multi-year project to search for the progenitors of novae in M31. The survey used Liverpool Telescope images of each nova in outburst to reveal the position of the quiescent system in archival HST data. At the distance of M31, the red giant branch is largely resolvable in the HST data, allowing novae with red giant secondaries to be directly imaged. The resulting catalogue contained 38 spectroscopically confirmed novae and we were able to recover the likely progenitor systems for 11 of these. A full statistical analysis of the survey estimates the proportion of M31 novae with evolved secondaries to be approximately 40%, much higher than was previously thought. The spatial distribution of these novae within M31 has also revealed that we may expect any Type Ia supernovae originating from such systems to be more common in younger stellar populations compared to older populations.