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MEERKAT DATA REVEALS UNEXPECTED FEATURES IN DISTANT GALAXY BY SARAO An international team of astronomers has uncovered unusual features in a radio galaxy using data from South Africa’s MeerKAT telescope, a precursor to the SKA. The radio galaxy resides in a galaxy cluster located around 222 million light years from Earth, and is one of the brightest objects in the southern sky at radio wavelengths. The classical picture of a radio galaxy consists of an active galactic nucleus that hosts a growing supermassive black hole, shooting out two jets of plasma filled with particles that move at speeds close to the speed of light. The material within the jets eventually slows down and billows out, forming large radio lobes. The galaxy in question is characterised by two such lobes of very bright radio emission, but, unexpectedly, the new observations with MeerKAT show multiple previously unseen parallel threads of radio emission connecting the two lobes which are thought to be caused by synchrotron radiation, explains Dr Mpati Ramatsoku, a Research Fellow at Rhodes University and lead author of the study.
The nature of these unusual features is unclear; they may be unique to the galaxy because of its harsh environment, or could be common in radio galaxies but, so far, we have been unable to detect them due to instrument limitations. Dr Ramatsoku adds that understanding the nature and the physics of these threads could open a new science case for sensitive radio interferometers like MeerKAT and, in the future, the SKA. “Such serendipitous discoveries are very important for MeerKAT because it highlights its incredible capacity for finding the ‘unknown unknowns’ in our Universe,” said Prof. Oleg Smirnov, Head of the Radio Astronomy Research Group at SARAO. Read more on the SARAO website. Above: Image reconstructed using radio emission data from MeerKAT at 1000 MHz, showing unusual parallel threads connecting radio emission lobes of the galaxy (M. Ramatsoku et al., 2020, A&A). Credit: Rhodes University/INAF/SARAO
SUCH SERENDIPITOUS DISCOVERIES ARE VERY IMPORTANT FOR MEERKAT BECAUSE IT HIGHLIGHTS ITS INCREDIBLE CAPACITY FOR FINDING THE ‘UNKNOWN UNKNOWNS’ IN OUR UNIVERSE. Professor Oleg Smirnov, Head of the Radio Astronomy Research Group at SARAO
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