Solving the Supernova Type Ia Progenitor Puzzle: Building Bridges between Theory and Observation

Smithsonian Institution Astrophysical Observatory, Cambridge MA

Investigators

Abstract

Supernovae (SNe), or the explosions of massive stars, are a critical component in measuring and understanding the accelerated expansion of the universe. This is possible because astronomers are able to standardize a certain type of SNe (Type Ia) observed across the universe, due to similarities in their brightnesses. However, there remain uncertainties in the standardization process, some of which stem from an incomplete understanding of the progenitors of Type Ia supernovae. A research team led by the Smithsonian Institution Astrophysical Observatory will carry out a project to study the astrophysical systems within which the white dwarf stars that become Type Ia SNe are primed to explode. The work will focus on the contribution of triple-star systems relative to binaries as SNe progenitors. The results of this research will be of great interest to the general public, not only because of the fascination of Type Ia supernovae, but also because the work on three-star systems will produce eye-catching animations. The researchers will work with science education experts to create planetarium shows whose subjects will be derived from the SNe research. Research done through this program will become part of the narrative thread of a high school summer course the principal investigator teaches, and high school students, together with undergraduate students, will participate in the research. The objectives of the project are twofold. The researchers will (1) determine the contribution of triple-star systems relative to binaries, and (2) produce a cutting edge population synthesis code for public use, which employs state-of-the-art linkages between observations and evolutionary states, allowing diverse research groups to make meaningful comparisons of their results. To accomplish this, the scientists will conduct a systematic study of hierarchical triples in which the outer star contributes mass to an inner binary within a system that has the potential to form a Type Ia supernova. They will also include three-body dynamics and will thoroughly explore the parameter space, focusing on detectable signatures. The dynamics will provide crucial input in the development of a new type of population synthesis code that includes binaries and triples, and will have the distinctive feature of built-in expandable links to existing and developing data sets from a variety of sources. Better understanding SNe progenitors is especially important because wide-field surveys, including the NSF-sponsored Vera Rubin Observatory, are set to discover so many SNe per year that systematic uncertainties must be explored. Other areas that benefit are the study of cosmic enrichment, necessary for the development of life, and improved predictions of gravity wave signals. Furthermore, the three-body problem is itself of great intellectual interest, and the work on mass transfer in triples will open new avenues of research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.