Dusty Magnetohydrodynamics in Star Forming Regions

TL;DR

This paper explores the role of dust grains and their interactions with magnetic fields in the dense, dark regions where stars form, emphasizing their importance in magnetohydrodynamic models of star formation.

Contribution

It highlights the significance of dust grain dynamics and grain-related processes in magnetohydrodynamic models of star-forming regions, an aspect often overlooked.

Findings

Recombination on grains removes gas phase ions effectively.

Collisions of neutrals with charged grains influence magnetic coupling.

Grain dynamics are crucial for modeling large-scale collapse and shock structures.

Abstract

Star formation occurs in dark molecular regions where the number density of hydrogen nuclei, nH, exceeds 10^4 cc and the fractional ionization is 10^-7 or less. Dust grains with sizes ranging up to tenths of microns and perhaps down to tens of nanometers contain just under one percent of the mass. Recombination on grains is important for the removal of gas phase ions, which are produced by cosmic rays penetrating the dark regions. Collisions of neutrals with charged grains contribute significantly to the coupling of the magnetic field to the neutral gas. Consequently, the dynamics of the grains must be included in the magnetohydrodynamic models of large scale collapse, the evolution of waves and the structures of shocks important in star formation.