Jan Rybizki

For the next Gaia data release I am developing a pipeline that infers binary stellar parameters from BPRP spectra. Our group also facilitated the use of Gaia DR2 by preparing a mock catalog and a geometric distance catalog which can be queried via ADQL. We also looked into close stellar encounters exploiting the 7.2mio radial velocities provided by Gaia. Building up on that we have identified likely close encounter candidates from the 1.33 bn sources with parallaxes and proper motions for follow-up observations.

During my PhD thesis I have written Chempy, a flexible chemical evolution code, that can predict the elemental abundance distribution of the interstellar medium over time. By comparing to the elemental abundances found in stars we are able to infer fundamental parameters of the Milky Way, like the stellar initial mass function (IMF). With my summer student Oliver Philcox, we tested how well different nucleosynthetic yield calculations of core-collapse Supernovae are able to reproduce the Solar elemental abundances. For the most abundant elements this already works reasonably well and we can also predict optimal parameters and yield sets for hydrodynamical simulations.