A galaxy speeding through space at a jaw-dropping 2 million mph (3.2 million km/h) has collided with others, creating a dramatic cosmic event.
This collision, observed in a group of galaxies called Stephan’s Quintet, has been seen in incredible detail using one of Earth’s most advanced telescopes.
Stephan’s Quintet, a group of five galaxies first discovered in 1877, is known for its chaotic history of past galaxy collisions.
The latest impact, caused by the fast-moving galaxy NGC 7318b, triggered a massive shock wave similar to a “sonic boom from a jet fighter.” This shock wave is one of the most striking phenomena ever observed in space.
The event was captured using the WEAVE spectrograph, a cutting-edge instrument attached to the William Herschel Telescope in La Palma, Spain.
WEAVE, which cost €20 million (£16.7 million), is designed to map stars and gases in incredible detail, providing new insights into the Milky Way and galaxies across the universe.
A closer look at the collision
The international team of over 60 astronomers found that as NGC 7318b sped through Stephan’s Quintet, it created a powerful shock wave moving through cold and hot gas.
When the shock passed through pockets of cold gas, it traveled at hypersonic speeds, ripping electrons from atoms and leaving a glowing trail of charged gas.
However, the shock behaved differently when it moved through hot gas, becoming weaker. Instead of causing major disruption, it compressed the gas, producing radio waves detectable by telescopes like the Low Frequency Array (LOFAR).
“This dual nature of the shock was a surprise,” said Dr. Marina Arnaudova, the study’s lead researcher from the University of Hertfordshire. “The collision reawakened dynamic activity in the group, creating a shock powerful enough to transform the surrounding gas.”
Revolutionizing astronomy
The unprecedented level of detail was possible because WEAVE’s advanced technology combined data from other tools like LOFAR, the Very Large Array (VLA), and the James Webb Space Telescope (JWST). WEAVE uses a spectroscope to break down light from stars and gas, revealing their composition and movement.
This event marks just the beginning for WEAVE. Astronomers believe it will transform our understanding of how galaxies form and evolve.
Professor Gavin Dalton, WEAVE’s principal investigator, said: “These observations not only show the incredible detail of Stephan’s Quintet’s collision but also hint at the potential for discovering faint, distant galaxies at the limits of our technology.”
Dr. Marc Balcells, director of the Isaac Newton Group of Telescopes, added, “This is just the start of what WEAVE will uncover in the coming years.”
This groundbreaking study, published in Monthly Notices of the Royal Astronomical Society, showcases the power of modern astronomy and offers a glimpse into the violent, beautiful nature of the universe.
Source: Royal Astronomical Society.
