Astronomers have discovered a mysterious cosmic phenomenon known as ODD Radio Circles (ORC). These unusual annular radio structures were first detected around some galaxies in 2021, leaving scientists puzzled about how they are formed.
Recent observations of one of the ORCs, named “Clover Liszt” (Cloverleaf), have provided scientists with new insights into their origins. Researchers believe that Cloverleaf was created through the collision of large-scale groups of galaxies. X-ray satellite observations revealed the structure in a new light, allowing scientists to identify the rapid acceleration of particles resulting from the merger, which produced the observed X-ray radiation.
This marks the first time that X-ray radiation associated with an ORC has been recorded, proving crucial in deciphering the origins of Cloverleaf. Using X-ray radiation, scientists were able to map the distribution of gas within the Cloverleaf structure, revealing that it formed as a result of the merger of two independent groups of galaxies. The increase in total mass during the merger heats the surrounding gas, generating X-rays with temperatures reaching about 15 million degrees Fahrenheit.
Scientists speculate that the acceleration of particles in the ORC may be linked to a black hole that experienced intense activity in the past, with relic electrons from this activity being re-accelerated during the merger process. ODD Radio Circles (ORC) are extremely challenging to detect due to their faint signals, and only 8 such formations have been identified outside our galaxy. Some ORCs are so large that they can envelop entire galaxies or multiple galaxies.
The research team plans to delve deeper into these mysterious structures using telescopes such as Erosita and XMM-Newton to further study their nature and origins, shedding more light on these enigmatic cosmic phenomena.