IRAS 16293: A "Magnetic" Tale of Two Cores

TL;DR

This study uses high-resolution polarization observations of IRAS 16293 to reveal distinct magnetic field structures in its two protostellar components, supporting theories of magnetic influence in star formation.

Contribution

It provides detailed polarization maps showing different magnetic field morphologies in the binary components, highlighting the role of magnetic fields in early star formation stages.

Findings

Source A exhibits an hourglass magnetic field shape.

Source B has a relatively ordered, undeformed magnetic field.

Magnetic energy exceeds turbulent energy but is comparable to centrifugal energy.

Abstract

We present polarization observations of the dust continuum emission from IRAS 16293 which is a Class 0 protostar and is known to have at least two components, source A and B. These measurements were conducted by the Submillimeter Array (SMA) at a frequency of ~341 GHz and with high angular resolution (~2-3 arcseconds). We find that the large scale global direction of the field, which is perpendicular to the observed polarization, appears to be along the dust ridge where the emission peaks. On smaller scales we find that the field structure is significantly different for the two components of the binary. The first component, source A, shows a magnetic field structure which is "hourglass" shaped as predicted from theoretical models of low mass star formation in the presence of strong magnetic fields. However, the other component, source B, shows a relatively ordered magnetic field with no evidence of any deformation. There is an observed decrease in polarization towards the center. Our calculations show that in IRAS 16293 the magnetic energy is stronger than the turbulent energy but is approximately similar to the centrifugal energy. Our results provide additional evidence to show that the two protostars appear to be in different stages during their evolution.