Informazioni sull’evento


Attenzione: a seguito delle disposizioni per il contenimento della diffusione del coronavirus, i seminari saranno in modalità online. Il link per il collegamento verrà reso disponibile nei giorni precedenti la data del seminario. Qui, invece, la playlist dei remote talks già messi in rete »

Astrophysics Talk

Low-alpha stars in the Gaia-ESO survey: exotic travellers in our galaxy

Xiaoting FU (KAVLI - Peking University)

Tuesday 01/10/2019 @ 14:30, Sala IV piano Battiferro

We exploit the large high-resolution spectroscopic survey Gaia-ESO and the Gaia astrometry to study the properties of the population of low-alpha stars, which are thought to be formed in dwarf galaxies and later accreted into the Milky Way. In total, we select 43 low-alpha stars belonging both to the Galactic bulge, disc, and the halo. They show significantly lower [Mg/Fe] abundance compared to other Galactic field stars with similar [Fe/H] but are similar to stars belonging to dwarf galaxies. By considering their kinematic and dynamical parameters, we conclude that half of them are likely to be associated with Gaia-Enceladus, which has recently been proposed as a major accreted component of the local halo. Seven of the selected low-alpha stars belong to, at least are locate in, the Galactic bulge. The origin of the rest low-alpha stars are still unknown.