2022/03/14 by R. P. Norris, Ray P. Norris, J. D. Collier +22 · 50 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Galaxy #Library science #Pathfinder #Physics #Polarization (electrochemistry) #Radio Astronomy Observations and Technology #Radio astronomy #Radio galaxy #Radio telescope #Redshift #Sensitivity (control systems) #Spectral index #Spectral line #astro-ph.GA
paper · pdf · open access · doi:10.1093/mnras/stac701
published in Monthly Notices of the Royal Astronomical Society 513(1), 1300-1316 (Oxford University Press) · Accepted by MNRAS
openalex publication_date 2022/03/14 · arxiv created 2022/03/20 · arxiv updated 2022/03/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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 uJy/bm). In addition to the new images, which reveal a complex internal structure consisting of multiple arcs, we also present polarisation and spectral index maps. Based on these new data, we consider potential mechanisms that may generate the ORCs.