Discovery of a new extragalactic circular radio source with ASKAP: ORC J0102-2450

TL;DR

This paper reports the discovery of a new Odd Radio Circle (ORC) using ASKAP, analyzing its properties and potential origins, and encouraging further searches for similar structures to understand their nature.

Contribution

The paper presents the first detailed observation and analysis of a new ORC, expanding knowledge of these rare radio structures and proposing possible formation scenarios.

Findings

Discovered ORC J0102-2450 with a 70 arcsec diameter

Possible association with a central elliptical galaxy at z ~ 0.27

Suggested origins include relic lobes or giant blast waves

Abstract

We present the discovery of another Odd Radio Circle (ORC) with the Australian Square Kilometre Array Pathfinder (ASKAP) at 944 MHz. The observed radio ring, ORC J0102-2450, has a diameter of ~70 arcsec or 300 kpc, if associated with the central elliptical galaxy DES J010224.33-245039.5 (z ~ 0.27). Considering the overall radio morphology (circular ring and core) and lack of ring emission at non-radio wavelengths, we investigate if ORC J0102-2450 could be the relic lobe of a giant radio galaxy seen end-on or the result of a giant blast wave. We also explore possible interaction scenarios, for example, with the companion galaxy, DES J010226.15-245104.9, located in or projected onto the south-eastern part of the ring. We encourage the search for further ORCs in radio surveys to study their properties and origin.