Sven Buder

Sven Buder  ( Germany )

buder @

Galactic Archaeology with Large Stellar Surveys

In the Gaia era, this PhD project will help to complete our understanding of ages and formation histories, and at a higher level the Milky Way with its components.

To solve this "Milky Way puzzle", automated spectral analysis of large numbers (>10 000) of stars with stellar surveys such as the ongoing GALAH and Gaia-ESO will be used. These ground-based studies are conducted to maximize Gaia's scientific legacy: while Gaia will deliver photometry, 3-D positions, and proper motions for V<20 as well as radial velocities, metallicities, and stellar parameters for V<17, a more detailed abundance analysis for the observed stars will be needed.

For this purpose, we are using the spectrum synthesis program Spectroscopy Made Easy (SME) by Valenti & Piskunov (1996) and the data-driven label determination program The Cannon by Ness et al. 2015 in combination. In the first step, SME will be used on a representative subsample of the survey(s) to determine parameters and abundances at high S/N. The chosen subsample will be used as training set for The Cannon to efficiently achieve the best generate model for the survey with its particular setup. This novel combination leverages SME?s flexibility and physical realism with The Cannon?s efficiency and robustness also at low S/N.

Supervisor:   Karin Lind  ( MPIA )

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