Faint arc-minute extended radio emission around Cygnus X-3

TL;DR

This study presents deep radio observations around Cygnus X-3, revealing faint extended emission possibly linked to the microquasar and discovering a nearby Fanaroff-Riley II galaxy, enhancing understanding of its environment.

Contribution

It provides the deepest radio images of Cygnus X-3 at cm wavelengths and reports the detection of faint extended emission and a nearby radio galaxy.

Findings

Detection of faint extended radio emission near Cygnus X-3

Possible non-thermal nature of the extended emission

Discovery of a nearby Fanaroff-Riley II radio galaxy

Abstract

Aims. We revisit the vicinity of the microquasar Cygnus X-3 at radio wavelengths. We aim to improve our previous search for possible associated extended radio features/hot spots in the position angle of the Cygnus X-3 relativistic jets focusing on shorter angular scales than previously explored. Methods. Our work is mostly based on analyzing modern survey and archive radio data, mainly including observations carried out with the Very Large Array and the Ryle Telescopes. We also used deep near-infrared images that we obtained in 2005. Results. We present new radio maps of the Cygnus X-3 field computed after combining multi-configuration Very Large Array archive data at 6 cm and different observing runs at 2 cm with the Ryle Telescope. These are probably among the deepest radio images of Cygnus X-3 reported to date at cm wavelengths. Both interferometers reveal an extended radio feature within a few arc-minutes of the microquasar position, thus making our detection more credible. Moreover, this extended emission is possibly non-thermal, although this point still needs confirmation. Its physical connection with the microquasar is tentatively considered under different physical scenarios. We also report on the serendipitous discovery of a likely Fanaroff-Riley type II radio galaxy only 3 arc-minute away from Cygnus X-3.