The Galactic bulge: doing Galactic archaeology at the Milky Way’s heart

Dr. Alvaro Rojas

PUC

Abstract:

The chemical abundance and kinematic patterns of long-lived low mass stars
represent and open book for reading the history and physical mechanisms
involved in the formation and chemodynamical evolution of the different
stellar populations assembling the present day Milky Way. The Galactic
bulge, being a massive structural component of the Galaxy, is crucial in
our observational quest to understand galaxy evolution as a whole. Our
understanding of the Galactic bulge’s nature has substantially increased
in the last decade, mainly driven by the data provided by recent large
scale photometric and high-resolution spectroscopic surveys.
Paradoxically, as observational evidence accumulates, the nature of the
Galactic bulge has proven to be rather complex, with structural, kinematic
and chemical properties leading to conclusions often contradictory. As
already suggested from the bimodal nature of the metallicity distribution
function, the bulge seems to be the product of the spatial coexistence of
two groups of metal-rich and metal-poor stars, with different spatial
distributions, kinematics, alpha-enhancements, and seemingly, different
ages. In this talk I will review the challenges and some of the lessons
learned from the spectroscopic census of chemistry and kinematics of bulge
stars.