Seminar: The metal-poor universe in 3D non-LTE
- Date: 11 September 2024, 15:30–16:30
- Location: Ångström Laboratory, 101136Å and Zoom: https://uu-se.zoom.us/j/63294871517.
- Type: Seminar
- Lecturer: Cis Lagae, Stockholm University
- Organiser: Division of Astronomy and Space Physics, Department of Physics and Astronomy
- Contact person: Adam Rains
I will present an overview of the research carried out during my PhD which focused on metal-poor, low-mass Milky Way stars, aiming to understand the nature of the first stars and galactic chemical evolution. To reach this goal, we require knowledge of the chemical composition of (metal-poor) stars, which are conventionally determined from a simple 1D LTE abundance analysis. To reduce large systematic errors in abundance measurements and prevent erroneous conclusions, it is necessary to compute synthetic spectra in non-LTE and with 3D stellar atmospheres, simultaneously. For this purpose, I have updated the STAGGER-grid of 3D model atmospheres in the subgiant region (logg<3.5) and prepared the STAGGER-grid for public release. In addition, I am working on a grid of 3D non-LTE spectra of the Ca II triplet lines, which are commonly used for abundance analysis and radial velocity determination in metal-poor stars.
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We shall leave for lunch at around 12:15. There will be fika before the seminar.