Odd Radio Circles are large, circular astronomical objects which are bright around the edges at radio wavelengths. Theories on what causes these mysterious objects range from galactic shockwaves to the throats of wormholes. The new image from SARAO’s MeerKAT radio telescope is providing astronomers with more information to help narrow down those theories.
This composite image from SARAO’s MeerKAT radio telescope and the Dark Energy Survey shows an Odd Radio Circle called ORC 1 (green). Image credit: J. English, University of Manitoba / EMU / MeerKAT / DES / CTIO.
First discovered in 2020, Odd Radio Circles (ORCs) quickly became objects of fascination.
There are now three leading theories to explain what causes them:
(i) ORCs could be the remnant of a huge explosion at the center of their host galaxy, like the merger of two supermassive black holes;
(ii) they could be powerful jets of energetic particles spewing out of the galaxy’s center;
(iii) they might be the result of a starburst ‘termination shock’ from the production of stars in the galaxy.
To date ORCs have only been detected using radio telescopes, with no signs of them when astronomers have looked for them using optical, infrared, or X-ray telescopes.
“Continuing to observe these objects will provide us with more clues,” said Dr. Jordan Collier, an astronomer with the Inter-University Institute for Data Intensive Astronomy.
“People often want to explain their observations and show that it aligns with our best knowledge.”
“To me, it’s much more exciting to discover something new, that defies our current understanding.”
ORCs are enormous — about a million light-years across, much bigger than our Milky Way Galaxy. Despite this, these objects are hard to see.
“Only five ORCs have ever been revealed in space,” said Professor Ray Norris, an astronomer at Western Sydney University and CSIRO.
“We know ORCs are rings of faint radio emissions surrounding a galaxy with a highly active black hole at its centre, but we don’t yet know what causes them, or why they are so rare.”
“For now, ASKAP and MeerKAT are working together to find and describe these objects quickly and efficiently,” said Professor Elaine Sadler, chief scientist of CSIRO’s Australia Telescope National Facility.
The team’s paper will be published in the Monthly Notices of the Royal Astronomical Society.
Source link: https://www.sci.news/astronomy/odd-radio-circle-meerkat-image-10639.html
