MeerKAT uncovers the physics of an odd radio circle. Issue 1 (24th March 2022)

• Record Type: Journal Article
• Authors: Norris, Ray P; Collier, J D; Crocker, Roland M; Heywood, Ian; Macgregor, Peter; Rudnick, L; Shabala, Stas; Andernach, Heinz; da Cunha, Elisabete; English, Jayanne; Filipović, Miroslav; Koribalski, Bärbel S; Luken, Kieran; Robotham, Aaron; Sekhar, Srikrishna; Thorne, Jessica E; Vernstrom, Tessa
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 513:Issue 1(2022)
• Page Start: 1300
• Page End: 1316
• Publication Date: 2022-03-24
• Subjects: galaxies: general -- radio continuum: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac701
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Odd radio circles (ORCs) are recently-discovered faint diffuse circles of radio emission, of unknown cause, surrounding galaxies at moderate redshift ( z ∼ 0.2 – 0.6). Here, we present detailed new MeerKAT radio images at 1284 MHz of the first ORC, originally discovered with the Australian Square Kilometre Array Pathfinder, with higher resolution (6 arcsec) and sensitivity (∼ 2.4 μJy/beam). In addition to the new images, which reveal a complex internal structure consisting of multiple arcs, we also present polarization and spectral index maps. Based on these new data, we consider potential mechanisms that may generate the ORCs.