Yet another Odd Radio Circle?

TL;DR

This paper reports the first low-frequency detection of an Odd Radio Circle using LOFAR, expanding the understanding of these mysterious diffuse radio sources and their potential origins.

Contribution

It presents the serendipitous discovery of an Odd Radio Circle at 144 MHz, the first such detection at very low frequencies, providing new observational data.

Findings

First low-frequency detection of an ORC with LOFAR

Supports the idea that ORCs are observable across a broad frequency range

Provides new data for understanding ORC origins

Abstract

The Odd Radio Circles are newly identified diffuse radio sources at ~1 GHz frequency, with edge-brightened nearly circular morphology, which is remarkably similar to supernova remnants although a physical association with previous population of Galactic supernova remnants is challenging due to detections of the Odd Radio Circles at high Galactic latitudes. Here, a serendipitous identification of a new source in a LOFAR 144 MHz image with similar morphology as that of Odd Radio Circles is reported. This is the first reported identification of an Odd Radio Circle at a very low frequency and with the LOFAR.