Work

An extended and extremely thin gravitational arc from a lensed compact symmetric object at redshift of 2.059

Year: 2025

Type: article

Abstract: ABSTRACT Compact symmetric objects (CSOs) are thought to be short-lived radio sources with two lobes of emission that are separated by less than a kpc in projection. However, studies of such systems at high redshift are challenging due to the limited resolution of present-day telescopes, and can be biased to the most luminous objects. Here, we report imaging of a gravitationally lensed CSO at a redshift of 2.059 using very long baseline interferometry at 1.7 GHz. The data are imaged using Bayesian forward modelling deconvolution, which reveals a spectacularly extended and thin gravitational arc, and several resolved features within the lensed images. The surface brightness of the lensing-corrected source shows two mini-lobes separated by 642 pc in projection, with evidence of multiple hotspots that have brightness temperatures of $10^{8.6}$ to $10^{9.2}$ K, and a total luminosity density of $10^{26.3}$ W Hz$^{-1}$. By combining the well-resolved radio source morphology with previous multiwavelength studies, we conclude that this object is likely a CSO of type 2, and that the properties are consistent with the bow-shock model for compact radio sources. Our analysis highlights the importance of combining high-quality data sets with sophisticated imaging and modelling algorithms for studying the high-redshift Universe.

Source: Monthly Notices of the Royal Astronomical Society Letters

DOI: 10.1093/mnrasl/slaf039

Authors: J P McKean, C Spingola, D M Powell, S Vegetti

Institutions: University of Groningen, South African Radio Astronomy Observatory, University of Pretoria, Istituto di Radioastronomia di Bologna, Max Planck Institute for Astrophysics

Language: English

Topic: Astrophysical Phenomena and Observations

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $1,451