Vorticity from irrotationally forced flow

TL;DR

This paper investigates how vorticity is generated in the interstellar medium's turbulence, which is mainly driven by supernova explosions, by examining the effects of rotation, shear, and baroclinicity.

Contribution

It provides a detailed analysis of the mechanisms contributing to vorticity generation in the ISM, clarifying their relative effectiveness.

Findings

Rotation, shear, and baroclinicity can generate vorticity in the ISM.

Vorticity influences turbulent diffusion in the interstellar medium.

The study quantifies the impact of different mechanisms on vorticity production.

Abstract

In the interstellar medium the turbulence is believed to be forced mostly through supernova explosions. In a first approximation these flows can be written as a gradient of a potential being thus devoid of vorticity. There are several mechanisms that could lead to vorticity generation, like viscosity and baroclinic terms, rotation, shear and magnetic fields, but it is not clear how effective they are, neither is it clear whether the vorticity is essential in determining the turbulent diffusion acting in the ISM. Here we present a study of the role of rotation, shear and baroclinicity in the generation of vorticity in the ISM.