Interaction of HVCs with the Outskirts of Galactic Disks: Turbulence

TL;DR

This paper uses numerical simulations to demonstrate that the infall of compact high velocity clouds can generate turbulence in the outer regions of galactic disks, independent of star formation processes.

Contribution

It introduces a novel simulation study showing how CHVCs interacting with galactic outskirts can drive turbulence without star formation.

Findings

HVC infall induces turbulence in outer galactic disks

Simulations show CHVCs can generate random motions in HI regions

Turbulence can be driven by external gas accretion processes

Abstract

There exist many physical processes that may contribute to the driving of turbulence in galactic disks. Some of them could drive turbulence even in the absence of star formation. For example, hydrodynamic (HD) or magnetohydrodynamic (MHD) instabilities, frequent mergers of small satellite clumps, ram pressure, or infalling gas clouds. In this work we present numerical simulations to study the interaction of compact high velocity clouds (CHVC) with the outskirts of magnetized gaseous disks. With our numerical simulations we show that the rain of small HVCs onto the disk is a potential source of random motions in the outer parts of HI disks.