Magnetic Field Analysis of the Bow and Terminal Shock of the SS433 Jet

TL;DR

This study uses polarization and Faraday tomography to analyze magnetic field structures and shock features in the SS433 jet region of W50, revealing complex magnetic alignments and multiple line-of-sight components.

Contribution

It provides the first detailed magnetic field vector map of the SS433 jet interaction region and interprets the observed structures with new insights into their magnetic and physical properties.

Findings

Magnetic fields align with intensity structures, indicating ordered magnetic configurations.

Multiple Faraday components suggest complex line-of-sight magnetic structures.

The X-ray ring is likely part of a helical structure, not a radio ring.

Abstract

We report a polarization analysis of the eastern region of W50, observed with the Australia Telescope Compact Array (ATCA) at 1.4 - 3.0 GHz. In order to study the physical structures in the region where the SS433 jet and W50 interact, we obtain an intrinsic magnetic field vector map of that region. We find that the orientation of the intrinsic magnetic field vectors are aligned along the total intensity structures, and that there are characteristic, separate structures related to the jet, the bow shock, and the terminal shock. The Faraday rotation measures (RMs), and the results of Faraday Tomography suggest that a high intensity, filamentary structure in the north-south direction of the eastern-edge region can be separated into at least two parts to the north and south. The results of Faraday Tomography also show that there are multiple components along the line of sight and/or within the beam area. In addition, we also analyze the X-ray ring-like structure observed with XMM-Newton. While the possibility still remains that this X-ray ring is real, it seems that the structure is not ring-like at radio wavelengths. Finally, we suggest that the structure is a part of the helical structure that coils the eastern ear of W50.