Magnetic Fields from Filaments to Cores

TL;DR

This paper investigates the role of magnetic fields in star formation by analyzing dust polarization observations in filamentary clouds and dense cores, revealing scale-dependent magnetic influences and new magnetic structures.

Contribution

It provides new observational insights into magnetic field orientations and structures across different scales in star-forming regions, highlighting their varying importance.

Findings

Magnetic fields are either perpendicular or parallel to filament axes.

Magnetic field orientations correlate with local velocity gradients.

New magnetic features like converging lines are observed in collapsing cores.

Abstract

How important is the magnetic (B-) field when compared to gravity and turbulence in the star-formation process? Does its importance depend on scale and location? We summarize submm dust polarization observations towards the large filamentary infrared dark cloud G34 and towards a dense core in the high-mass star-forming region W51. We detect B-field orientations that are either perpendicular or parallel to the G34 filament axis. These B-field orientations further correlate with local velocity gradients. Towards three cores in G34 we find a varying importance between B-field, gravity, and turbulence that seems to dictate varying types of fragmentation. At highest resolution towards the gravity-dominated collapsing core W51 e2 we resolve new B-field features, such as converging B-field lines and possibly magnetic channels.