Formation and evolution of early-type galaxies. II. Models with quasi-cosmological initial conditions

TL;DR

This paper uses N-body simulations with quasi-cosmological initial conditions to model the formation and evolution of early-type galaxies, showing their properties align with observations and supporting the revised monolithic formation scheme.

Contribution

It presents detailed models of early-type galaxy formation from initial conditions to present-day properties, emphasizing early star formation and chemical enrichment within a cosmological context.

Findings

Models match observed structural properties

Chemical properties agree with data

Galactic winds are observed in models

Abstract

In this study, with the aid of N-Body simulations based on quasi-cosmological initial conditions, we have followed the formation and evolution of two models of early-type galaxies, from their separation from global expansion of the Universe to their collapse to virialized structures, the formation of stars and subsequent nearly passive evolution. The cosmological background we have considered is the Standard CDM. The models have significantly different nitial total mass. Particular care has been paid to the star formation process, heating and cooling of gas, and chemical enrichment. In both models star formation is completed within the first Gyrs of evolution. The structural properties of the present-day models are in good agreement with current observations. The chemical properties, mean metallicity and metallicity gradients also agree with available observational data. Finally, conspicuous galactic winds are found to occur. The models conform to the so-called revised monolithic scheme, because mergers of substructures have occurred very early in the galaxy life. Our results agree with those obtained in other similar recent studies, thus strengthening the idea that the revised monolithic scheme is the right trail to follow in the forest of galaxy formation and evolution.