Filament Formation via Collision-induced Magnetic Reconnection -- Formation of a Star Cluster

TL;DR

This study demonstrates that collision-induced magnetic reconnection (CMR) can produce dense filaments in molecular clouds that are capable of forming star clusters, with magnetic fields influencing the cluster's size and star formation rate.

Contribution

The paper confirms the formation of filaments via CMR and shows that such filaments can form star clusters with distinct properties influenced by magnetic fields.

Findings

CMR-filament formation is confirmed with simulations.

Star clusters form along the CMR-filament after collapse.

CMR filaments lead to smaller, magnetically confined star clusters with reduced star formation rates.

Abstract

A collision-induced magnetic reconnection (CMR) mechanism was recently proposed to explain the formation of a filament in the Orion A molecular cloud. In this mechanism, a collision between two clouds with antiparallel magnetic fields produces a dense filament due to the magnetic tension of the reconnected fields. The filament contains fiber-like sub-structures and is confined by a helical magnetic field. To show whether the dense filament is capable of forming stars, we use the \textsc{Arepo} code with sink particles to model star formation following the formation of the CMR-filament. First, the CMR-filament formation is confirmed with \textsc{Arepo}. Second, the filament is able to form a star cluster after it collapses along its main axis. Compared to the control model without magnetic fields, the CMR model shows two distinctive features. First, the CMR-cluster is confined to a factor of $\sim4$ smaller volume. The confinement is due to the combination of the helical field and gravity. Second, the CMR model has a factor of $\sim2$ lower star formation rate. The slower star formation is again due to the surface helical field that hinders gas inflow from larger scales. Mass is only supplied to the accreting cluster through streamers.