A giant radio jet of very unusual polarization in a single-lobed radio galaxy

TL;DR

This paper reports the discovery of a unique, highly polarized, one-sided giant radio jet from a massive black hole, challenging typical symmetry expectations and providing insights into magnetic field roles in jet stability.

Contribution

It presents the first detailed observation of an extremely large, predominantly one-sided, highly polarized radio jet with unusual magnetic field properties, expanding understanding of jet asymmetry.

Findings

Largest detected radio jet emitting strongly polarized synchrotron radiation

Jet exhibits increasing brightness asymmetry with distance from the nucleus

Features a predominantly toroidal magnetic field

Abstract

We report the discovery of a very unusual, predominantly one-sided radio galaxy CGCG049-033. Its radio jet, the largest detected so far, emits strongly polarized synchrotron radiation and can be traced all the way from the galactic nucleus to the hot spot located ~440 kpc away. This jet emanates from an extremely massive black-hole (mass > 10^9 times solar mass) and forms a strikingly compact radio lobe. To a surface brightness contrast of at least 20 no radio lobe is detected on the side of the counter-jet, which is similar to the main jet in brightness upto the scale of tens of kpc. Thus, contrary to the nearly universal trend, the brightness asymmetry in this radio galaxy increases with distance from the nucleus. With several unusual properties, including a predominantly toroidal magnetic field, this Fanaroff-Riley type II (FR-II) mega-jet is an exceptionally useful laboratory for testing the role of magnetic field in jet stabilization and radio lobe formation.