Gaia sibling stars as probes of chemodynamical evolution of the Milky Way’s disk
On 25 April 2018, the scientific team behind Gaia published the largest and most accurate three dimensional map of stars in the Galaxy. This map contains more than 1 billion positions, parallaxes, proper motions and brightness of stars and intends to provide with the necessary material to revolutionize our understanding about the structure and evolution of stars
and the Galaxy in which they live: our Milky Way.
Paula Jofré and Marcelo Tucci Maia from the Astronomy Nucleus, together an international team of astronomers from Bordeaux, Paris and PUC, Chile, proposed to exploit this map by identifying low-mass stars of spectral class FGK that are kinematically
connected and thus are expected to have the same origin (a.k.a sibling stars).
Thanks to this grant, they will investigate their chemical composition in order to understand (i) when stars are form in groups from a chemically homogeneous gas cloud and (ii) when the chemical composition of the atmosphere of FGK type stars reflects the composition of their birth cloud over its lifetime.
Understanding this is crucial for constraining chemodynamical models of the formation and evolution of the Galaxy, intended to quantify how chemical enrichment evolves with time as one generation of stars dies and donates its synthetized material to the
interstellar medium which then forms new stars. Such answers can be obtained only now that the accuracy of Gaia allow us to know with high confidence if stars are siblings. In addition, a detailed spectral analysis aiming at the highest precision is necessary to assess their chemical similarity.
The fund consists on collaborative trips which are intended to train PhD students into the field of high precision spectroscopy, data mining and Galactic dynamics. The collaborative trips of the post-docs have the specific objective to enable them foster new collaborations abroad, as well as gather international network, crucial for them progressing in their career and becoming the future leaders in the Field.
The ECOS-Conicyt project will enable a new collaboration not only at international but also at a national level between the new Astronomy Nucleus at UDP and the Astronomy Institute in PUC.