Radiation Magnetohydrodynamics Simulation of Proto-Stellar Collapse: Two-Component Molecular Outflow

TL;DR

This study uses advanced 3D RMHD simulations to explore the early stages of low-mass star formation, revealing a two-component molecular outflow driven by magnetic forces and providing insights for interpreting ALMA observations.

Contribution

It presents the first detailed 3D RMHD simulation of proto-stellar collapse including radiation transfer, showing the formation of a larger first core and a bipolar outflow with two components.

Findings

Outer first core has higher entropy and larger size than in barotropic models.

Bipolar outflow consists of two components driven by magnetic Lorentz force.

Shock heating occurs in the outflow, affecting observable properties.

Abstract

We perform a three-dimensional nested-grid radiation magneto-hydrodynamics (RMHD) simulation with self-gravity to study the early phase of the low-mass star formation process from a rotating molecular cloud core to a first adiabatic core just before the second collapse begins. Radiation transfer is handled with the flux-limited diffusion approximation, operator-splitting and implicit time-integrator. In the RMHD simulation, the outer region of the first core attains a higher entropy and the size of first core is larger than that in the magnetohydrodynamics simulations with the barotropic approximation. Bipolar molecular outflow consisting of two components is driven by magnetic Lorentz force via different mechanisms, and shock heating by the outflow is observed. Using the RMHD simulation we can predict and interpret the observed properties of star-forming clouds, first cores and outflows with millimeter/submillimeter radio interferometers, especially the Atacama Large Millimeter/submillimeter Array (ALMA).