VLBA polarimetric observations of the CSS quasar 3C147

TL;DR

This paper presents high-resolution VLBA polarimetric observations of the CSS quasar 3C147 at 5 and 8.4 GHz, revealing detailed polarization and magnetic field structures, and discusses the source's core and jet or hotspot nature.

Contribution

The study provides the first detailed polarimetric imaging of 3C147 at multiple frequencies, analyzing its magnetic field and structure to explore the core and jet or hotspot interpretations.

Findings

Detected a one-sided structure with a compact core region.

Mapped complex rotation measure distribution across the source.

Identified magnetic fields predominantly perpendicular to the source axis.

Abstract

Aims. We report new VLBA polarimetric observations of the compact steep-spectrum (CSS) quasar 3C147 (B0538+498) at 5 and 8.4GHz. Methods. By using multifrequency VLBA observations, we derived milliarcsecond-resolution images of the total intensity, polarisation, and rotation measure distributions, by combining our new observations with archival data. Results. The source shows a one-sided structure, with a compact region, and a component extending about 200 mas to the south-west. The compact region is resolved into two main components with polarised emission, a complex rotation measure distribution, and a magnetic field dominated by components perpendicular to the source axis. Conclusions. By considering all the available data, we examine the possible location of the core component, and discuss two possible interpretations of the observed structure of this source: core-jet and lobe-hot spot. Further observations to unambiguously determine the location of the core would help distinguish between the two possibilities discussed here.