The chemical evolution of the Galactic Bulge seen through micro-lensing events

TL;DR

This paper discusses how micro-lensing enables high-resolution spectral analysis of dwarf stars in the Galactic bulge, revealing elemental abundance trends similar to those in the solar neighborhood, and explores implications for galaxy evolution.

Contribution

It introduces the use of micro-lensing to obtain spectra of faint bulge dwarf stars, providing new insights into their chemical evolution and age distribution.

Findings

Elemental abundance trends in bulge dwarfs resemble those in the solar neighborhood.

Micro-lensing allows spectral analysis of faint bulge stars previously inaccessible.

Implications for the formation and evolution of the Galactic bulge.

Abstract

Galactic bulges are central to understanding galaxy formation and evolution. Here we report on recent studies using micro-lensing events to obtain spectra of high resolution and moderately high signal-to-noise ratios of dwarf stars in the Galactic bulge. Normally this is not feasible for the faint turn-off stars in the Galactic bulge, but micro-lensing offers this possibility. Elemental abundance trends in the Galactic bulge as traced by dwarf stars are very similar to those seen for dwarf stars in the solar neighbourhood. We discuss the implications of the ages and metallicity distribution function derived for the micro-lensed dwarf stars in the Galactic bulge.