Smoothed Particle Hydrodynamics in Thermal Phases of a One Dimensional Molecular Cloud

TL;DR

This study examines how ambipolar diffusion heating influences the thermal stability of a one-dimensional molecular cloud, revealing regions of thermal instability that could impact star and planet formation processes.

Contribution

It introduces a two-fluid smoothed particle hydrodynamics model to analyze ambipolar diffusion effects on thermal phases in magnetized molecular clouds.

Findings

Outer regions are thermally unstable due to isobaric instability.

Inner regions remain thermally stable.

Thermal instability may facilitate star and planet formation.

Abstract

We present an investigation on effect of the ion-neutral (or ambipolar) diffusion heating rate on thermal phases of a molecular cloud. We use the modeling of ambipolar diffusion with two-fluid smoothed particle hydrodynamics, as discussed by Nejad-Asghar & Molteni. We take into account the ambipolar drift heating rate on the net cooling function of the molecular clouds, and we investigate the thermal phases in a self-gravitating magnetized one dimensional slab. The results show that the isobaric thermal instability criterion is satisfied in the outer parts of the cloud, thus, these regions are thermally unstable while the inner part is stable. This feature may be responsible for the planet formation in the outer parts of a collapsing molecular cloud and/or may also be relevant for the formation of star forming dense cores in the clumps.