Chemical Evolution of the Carina Dwarf Spheroidal

TL;DR

This study models the chemical evolution of the Carina dwarf spheroidal galaxy using its CMD-constrained star formation history, highlighting the roles of galactic winds and re-accretion, and assessing elemental abundance patterns.

Contribution

It introduces a novel chemical evolution model that removes the SFH as a free parameter, relying on CMD data, and explores the effects of winds, re-accretion, and stripping.

Findings

Model successfully reproduces most elemental abundance patterns.

Neglecting stripping leads to overestimated gas fractions.

Re-accretion and winds are key to the galaxy's chemical evolution.

Abstract

We explore a range of chemical evolution models for the Local Group dwarf spheroidal (dSph) galaxy, Carina. A novel aspect of our work is the removal of the star formation history (SFH) as a `free parameter' in the modeling, making use, instead, of its colour-magnitude diagram (CMD)-constrained SFH. By varying the relative roles of galactic winds, re-accretion, and ram-pressure stripping within the modeling, we converge on a favoured scenario which emphasises the respective roles of winds and re-accretion. While our model is successful in recovering most elemental abundance patterns, comparable success is not found for all the neutron capture elements. Neglecting the effects of stripping results in predicted gas fractions approximately two orders of magnitude too high, relative to that observed.