Magnetic Fields Observed along the E-W Outflow of IRAS 16293-2422

TL;DR

This study uses 89 μm polarization observations to reveal a uniform magnetic field aligned with the outflow in IRAS 16293-2422, showing wavelength-dependent dust emission and magnetic field tracing different dust temperatures.

Contribution

First polarization measurements at 89 μm of IRAS 16293-2422, revealing magnetic field alignment with the outflow and wavelength-dependent dust emission peaks.

Findings

Magnetic field is uniform and aligned with the outflow at 89 μm.

Shorter wavelength data trace warmer dust and outflow-related magnetic fields.

Dust emission peaks shift from source B to A with increasing wavelength.

Abstract

Magnetic fields likely play an important role in the formation of young protostars. Multiscale and multiwavelength dust polarization observations can reveal the inferred magnetic field from scales of the cloud to core to protostar. We present continuum polarization observations of the young protostellar triple system IRAS 16293-2422 at 89 $\mu$m using HAWC+ on SOFIA. The inferred magnetic field is very uniform with an average field angle of 89$^\circ\pm$23$^\circ$ (E of N), which is different from the $\sim$170$^\circ$ field morphology seen at 850 $\mu$m at larger scales (> 2000 au) with JCMT POL-2 and at 1.3 mm on smaller scales (< 300 au) with ALMA. The HAWC+ magnetic field direction is aligned with the known E-W outflow. This alignment difference suggests that the shorter wavelength HAWC+ data is tracing the magnetic field associated with warmer dust likely from the outflow cavity, whereas the longer wavelength data are tracing the bulk magnetic field from cooler dust. Also, we show in this source the dust emission peak is strongly affected by the observing wavelength. The dust continuum peaks closer to source B (northern source) at shorter wavelengths and progressively moves toward the southern A source with increasing wavelength (from 22 $\mu$m to 850 $\mu$m).