An Empirical View to the Early Chemical Evolution of Bulge/Disk Galaxies

Alvio Renzini

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An Empirical View to the Early Chemical Evolution of Bulge/Disk Galaxies

Alvio Renzini

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Abstract

Scaling from the empirical metal yield as measured in clusters of galaxies, it is inferred that early in the evolution of the Galaxy the bulge stellar population has produced $\sim 10^9\msun$ of metals, at least 5 times more than the total metal content of the bulge today. It is argued that an early galactic wind from the starbursting bulge has pre-enriched a vast region around it, with these metals being able to enrich to $\sim 1/10$ solar of order of $5\times 10^{11}\msun$ of pristine material. From the empirical evidence that bulges come before disks, it is inferred that the Milky Way disk formed out of this pre-enriched material, which accounts for the scarcity of metal poor stars in the solar neighborhood, the so-called `G-Dwarf Problem'. High redshift observations are now becoming able to efficiently explore the $1.2\lsim z\lsim 3$ region of the universe, when disk formation and morphological differentiation may have taken place.

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Alvio Renzini. 2001-11-05. An Empirical View to the Early Chemical Evolution of Bulge/Disk Galaxies. https://arxiv.org/abs/astro-ph/0111090

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