Research Division Seminar
Pristine stars in the Milky-Way and beyond

Resumen

To understand the early phases of galaxy formation, metal-poor stars in the local universe play a special rôle, allowing to trace both how galactic assembly proceeds, and the conditions in which early star formation proceed. Metal-poor stars in our Galaxy and its satellites are fossils of these past processes and have therefore been the subject of intense dedicated searches and surveys since decades. Here I shall review some of the recent results that the « Pristine » narrow-band photometric survey at CFHT, has enabled, aided by the transformational information brought by the Gaia space mission. These results range from enravelling a very primordial disc in the Milky-Way, characterizing very pristine streams of stars in the galactic halo, and characterizing the co-existing halo and bulge populations in the inner parts of the Milky-Way. Finally, I will outline the plans to characterise further these extreme and very metal-poor stars with the new WEAVE multi-object facility that should start its science surveys early 2023.

To understand the early phases of galaxy formation, metal-poor stars in the local universe play a special rôle, allowing to trace both how galactic assembly proceeds, and the conditions in which early star formation proceed. Metal-poor stars in our Galaxy and its satellites are fossils of these past processes and have therefore been the subject of intense dedicated searches and surveys since decades. Here I shall review some of the recent results that the « Pristine » narrow-band photometric survey at CFHT, has enabled, aided by the transformational information brought by the Gaia space mission. These results range from enravelling a very primordial disc in the Milky-Way, characterizing very pristine streams of stars in the galactic halo, and characterizing the co-existing halo and bulge populations in the inner parts of the Milky-Way. 
Finally, I will outline the plans to characterise further these extreme and very metal-poor stars with the new WEAVE multi-object facility that should start its science surveys early 2023.