Evidence for a shock-compressed magnetic field in the northwestern rim of Vela Jr. from X-ray polarimetry

TL;DR

This study uses X-ray polarimetry to reveal a tangential magnetic field in the northwest rim of the young supernova remnant Vela Jr., challenging previous notions of magnetic field structures in such remnants.

Contribution

First X-ray polarimetric measurement of magnetic-field structure in Vela Jr, showing a tangential field in a young SNR, expanding understanding of magnetic configurations.

Findings

Detected a tangential magnetic field in Vela Jr's northwest rim.

Provided the first magnetic-field structure measurement in this SNR.

Challenged the typical radial magnetic field assumption in young SNRs.

Abstract

Synchrotron X-ray emission has been detected from nearly a dozen young supernova remnants (SNRs). X-rays of synchrotron origin exhibit linear polarization in a regular, non-randomly oriented magnetic field. The significant polarized X-ray emission from four such SNRs has already been reported on the basis of observations with the Imaging X-ray Polarimetry Explorer (IXPE). The magnetic-field structure as derived from IXPE observations is radial for Cassiopeia A, Tycho's SNR, and SN 1006, and tangential for RX J1713.7-3946. The latter together with the recent detection of a tangential magnetic field in SNR 1E 0102.2-7219 by the Australia Telescope Compact Array in the radio band shows that tangential magnetic fields can also be present in young SNRs. Thus, the dichotomy in polarization between young and middle-aged SNRs (radial magnetic fields in young SNRs, but tangential magnetic fields in middle-aged SNRs), previously noticed in the radio band, deserves additional attention. The present analysis of IXPE observations determines, for the first time, a magnetic-field structure in the northwestern rim of Vela Jr, also known as RX J0852.0-4622, and provides a new example of a young SNR with a tangential magnetic field.