Galactic archaeology with high temporal resolution

Willett, Emma ORCID: 0000-0002-7831-1402 (2023). Galactic archaeology with high temporal resolution. University of Birmingham. Ph.D.

Preview

Willett2023PhD.pdf
Text - Accepted Version
Available under License Creative Commons Attribution.
Download (24MB) | Preview

Abstract

The study of the formation and evolution of the Milky Way has entered a golden era. Galactic archaeology, enabled by high-precision astrometry and spectroscopy, has equipped us with rich maps of our Galaxy's kinematic and chemical structures. The next step is to build up a detailed chronology of the events and processes through which these structures formed. Asteroseismology -- the study and interpretation of stellar oscillations -- provides tight constraints on fundamental stellar parameters for thousands of evolved low-mass stars. From these, we obtain robust age estimates, which can be used as a cosmic clock. This thesis presents three works on the application of asteroseismology to Galactic archaeology.

First, new catalogues of stellar age estimates, combined with kinematic and chemical constraints, are presented. These catalogues sample the full history of the Galactic disc and probe the stellar halo, providing the basis for detailed studies of the Milky Way. This is demonstrated in the second work, in which one of these catalogues is applied to the question of the radial metallicity gradient of the thin disc. The results represent strong observational constraints for models of Galactic evolution and dynamical processes. Finally, a new technique to infer helium abundance from the luminosity of low-mass, core helium-burning field stars is described. This constrains the relative enrichment of helium and heavier elements in the Galaxy, with strong implications for stellar age determination.

These works demonstrate the potential for studies of the Milky Way with asteroseismic constraints. Though there are many open questions, it is clear that asteroseismology has a role to play in their solution and is paving the way to Galactic archaeology with high temporal resolution.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):