2025-05-30 –, Main Conference Room
In this talk, I will present the most recent chemical evolution models of the Milky Way. The SDSS-V Milky Way Mapper (MWM) survey will create the largest chemical map of our Galaxy by observing 5 million stars by 2027. MWM has observed 2 million stars to date, about 1 million will be made public in the first data release of MWM (DR19) in the Summer of 2025. Our group is not only leading the calibration/validation effort within SDSS for the first data release of MWM, but also uses its private data of nearly 400,000 stars to create an accurate history of the formation of our Galaxy, which consisted of a collision with another galaxy in the past. We modelled the evolution of 15 elements (Fe, Mg, O, Si, S, Ca, Ti, Na, Al, K, V, Cr, Mn, Co, Ni) in the entire Milky Way and divided the Galaxy into six regions based on the distance from the galactic center and modeled each of them separately. Within the six modelled regions the time of the second infall event ranges between 2.7 Gyr and 4.5 Gyr. The collision with the other galaxy happened earlier at the outermost regions, and as time elapsed it succesively reached the regions closer to the Galactic center. This means that the gravitational interaction between the potentially accreted dwarf galaxy and the early Milky Way started about 11.4 Gyr ago at the distance of R=14 kpc and finished about 2 billion years later, 9.5 Gyr ago at R=4 kpc.
