We have found a class of circular radio objects in the Evolutionary Map of the Universe Pilot Survey, using the Australian Square Kilometre Array Pathfinder telescope. The objects appear in radio images as circular edge-brightened discs, about one arcmin diameter, that are unlike other objects previously reported in the literature. We explore several possible mechanisms that might cause these objects, but none seems to be a compelling explanation.
Cite
@article{arxiv.2006.14805,
title = {Unexpected Circular Radio Objects at High Galactic Latitude},
author = {Ray P. Norris and Huib T. Intema and Anna D. Kapinska and Baerbel S. Koribalski and Emil Lenc and L. Rudnick and Rami Alsaberi and Craig Anderson and G. E. Anderson and E. Crawford and Roland Crocker and Jayanne English and Miroslav D. Filipovic and Andrew M. Hopkins and Natasha Hurley-Walker and Susumu Inoue and Kieran Luken and Peter Macgregor and Pero Manojlovic and Josh Marvil and Andrew N. O'Brien and Wasim Raja and Devika Shobhana and Tiziana Venturi and Jordan D. Collier and Catherine Hale and Aidan Hotan and Vanessa Moss and Matthew Whiting},
journal= {arXiv preprint arXiv:2006.14805},
year = {2021}
}