Deep Chandra and multicolor HST observations of the jets of 3C 371 and PKS 2201+044

TL;DR

This study provides multiwavelength imaging and spectroscopy of jets in two nearby radio galaxies, revealing their intermediate properties between FRI and FRII types and showing synchrotron emission with energy softening along the jets.

Contribution

It offers detailed multiwavelength observations and analysis of the jets in 3C 371 and PKS 2201+044, highlighting their intermediate characteristics and synchrotron emission behavior.

Findings

Jets show X-ray emission peaking closer to the nucleus.

Spectral energy distributions are consistent with synchrotron emission.

Electron energy decreases with distance along the jet.

Abstract

This paper presents multiwavelength imaging and broad-band spectroscopy of the relativistic jets in the two nearby radio galaxies 3C 371 and PKS 2201+044, acquired with Chandra, HST, VLA, and Merlin. Radio polarization images are also available. The two sources stand out as "intermediate'' between FRIs and FRIIs; their cores are classified as BL Lacs, although broad and narrow optical emission lines were detected at times. The multiwavelength images show jet morphologies with the X-ray emission peaking closer to the nucleus than the longer wavelengths. The jets are resolved at all wavelengths in a direction perpendicular to the jet axis. The jets SEDs are consistent with a single spectral component from radio to X-rays, interpreted as synchrotron emission. The SEDs show a progressive softening from the inner to the outer regions of the jet, indicating that the electron break energy moves to lower energies with distance from the core. Overall, the X-ray and multiwavelength properties of the jets of 3C 371 and PKS 2201+044 appear intermediate between those of FRIs and FRIIs.