Mysterious Radio Circles Unveiled
Radio circles discovered in the vastness of space have intrigued astronomers since 2019.
These odd radio circles (ORCs) have now been attributed to outflowing winds resulting from explosive events, such as supernovae.
A team from the University of California San Diego suggests that when numerous massive stars explode in close proximity, the force generated propels surrounding gas outward at speeds exceeding 1,200 miles per second.
The resultant outflowing winds create shells forming radio wave circles, exceeding 50,000 times the diameter of the Milky Way.
Formation Process Unveiled
Astrophysicist Alison Coil elaborates on the intriguing phenomenon, stating that ORCs often emerge when two large galaxies collide.
The merger channels gas into a confined region, sparking an intense burst of star formation.
Rapidly burning massive stars expel their gas as outflowing winds when they reach the end of their lifecycle.
A simulation designed by the research team reveals that outflowing galactic winds blow for 200 million years before ceasing, causing a forward-moving shock followed by a reverse shock, ultimately creating a radio ring.
Decoding the Mystery with Advanced Technology
The mystery surrounding ORCs began in 2019 when astronomers observed them using the Australian Square Kilometer Array Pathfinder (ASKAP).
Prior to this, ORCs had only been detected through radio emissions, lacking visual data.
The unusual discovery prompted various theories about its origins, including planetary nebulae and black hole mergers.
However, these were replaced with the hypothesis that starburst galaxies were responsible for creating ORCs.
The ASKAP telescope, with its 36 antennas, each 12 centimeters in diameter, played a crucial role in gathering optical and infrared imaging data to determine the age of stars within the ORC 4 galaxy.
Unveiling the Winds through Radio Data
Alison Coil emphasizes the significance of ORCs in providing a unique way to observe outflowing galactic winds through radio data and spectroscopy.
The ASKAP, recognized as the world’s fastest telescope, has the capacity to scan large portions of the sky, enabling the detection of ORCs stretching across vast distances.
Coil envisions a future where new large radio telescope arrays continue to discover more ORCs regularly.
This ongoing exploration will contribute to understanding the prevalence and life cycle of outflowing galactic winds, shedding light on the evolution of galaxies.
Unlocking the Secrets of ORCs for Future Exploration
In the pursuit of unraveling the mysteries of ORCs, Coil emphasizes the importance of studying central galaxies to determine if other ORCs experienced starburst events in the past.
Questions regarding the phases of massive galaxies and the transformation of spiral galaxies into elliptical forms remain open.
As new discoveries unfold with the aid of advanced telescopes, Coil expresses optimism about the wealth of knowledge that ORCs hold for astronomers in the future.
Science News