The chemical "double helix" of the old stellar populations in the Large Magellanic Cloud

Alessio Mucciarelli (Bologna University)

Despite several years of studies, the chemical evolution history of the Large Magellanic Cloud (LMC), as well as its star formation history,
is still poorly understood. Three main stellar populations have been identified in the LMC : (a) an old population, coeval to the
Galactic Halo, (b) an intermediate-age population (1-3 Gyr) that is the dominant one, and (c) a young component related to the
most recent bursts of star formation. The studies available so far based on high-resolution spectroscopy provide mainly
information about the chemical composition of the young/intermediate-age populations, while only a few studies on old
LMC globular clusters provide information about the chemistry in the oldest stars of LMC.

In this talk I will present the first homogeneous metallicity scale of old LMC clusters obtained using high-resolution spectroscopy,
discussing the differences in the main groups of elements between old LMC and Milky Way clusters.