Abundance Ratios in Stars vs. Hot Gas in Elliptical Galaxies: the Chemical Evolution Modeller Point of View

TL;DR

This paper presents a chemical evolution model for elliptical galaxies that simultaneously explains stellar and gas properties, including abundance ratios, by incorporating detailed ISM processes and dust effects, aligning well with observations.

Contribution

It introduces a self-consistent chemical evolution model that reproduces multiple galaxy relations and addresses the iron discrepancy by considering dust effects.

Findings

Model reproduces observed galaxy relations

Predicts abundance ratios consistent with observations

Addresses iron discrepancy through dust inclusion

Abstract

I will present predictions from chemical evolution model aimed at a self-consistent study of both optical (i.e. stellar) and X-ray (i.e.gas) properties of present-day elliptical galaxies. Detailed cooling and heating processes in the interstellar medium (ISM) are taken into and allow a reliable modelling of the SN-driven galactic wind. SNe Ia activity, in fact, may power a galactic wind lasting for a considerable amount of the galactic lifetime, even in the case for which the efficiency of energy transfer into the ISM per SN Ia event is less than unity. The model simultaneously reproduces the mass-metallicity, the colour-magnitude, the L_X - L_B and the L_X - T relations, as well as the observed trend of the [Mg/Fe] ratio as a function of sigma, by adopting the prescriptions of Pipino & Matteucci (2004) for the gas infall and star formation timescales. The "iron discrepancy", namely the too high predicted iron abundance in X-ray haloes of ellipticals compared to observations, can be solved by taking into account the existence of dust. I will make predictions on several abundance ratios in the ISM and compare them with the most recent observations.