Star formation in early-type galaxies: the role of stellar winds and kinematics

TL;DR

This paper investigates how stellar winds, supernovae, and galaxy kinematics influence star formation in early-type galaxies, revealing that cold gas forms a disc where new stars are born, consistent with observations.

Contribution

It demonstrates that stellar rotation leads to cold disc formation and subsequent star formation, a process previously unquantified in detailed hydrodynamical simulations.

Findings

Ordered rotation causes cold disc formation.

Star formation occurs mainly in the cold disc.

Cold gas masses align with observational data.

Abstract

Early-type galaxies (ETGs) host a hot ISM produced mainly by stellar winds, and heated by Type Ia supernovae and the thermalization of stellar motions. High resolution 2D hydrodynamical simulations showed that ordered rotation in the stellar component results in the formation of a centrifugally supported cold equatorial disc. In a recent numerical investigation we found that subsequent generations of stars are formed in this cold disc; this process consumes most of the cold gas, leaving at the present epoch cold masses comparable to those observed. Most of the new stellar mass formed a few Gyrs ago, and resides in a disc.