Distant Galaxies Crash and Produce a Massive Sonic Boom: Report
One of the most intense cosmic shock waves has been observed in Stephan’s Quintet, a group of galaxies located about 290 million light-years from Earth. The event was caused by the galaxy NGC 7318b colliding with four neighboring galaxies at an estimated speed of 3.2 million km per hour. The collision created a shock front that researchers likened to the sonic boom of a fighter jet. These findings, which could provide insight into the complex processes that shape galaxies, have been published in Monthly Notices of the Royal Astronomical Society.
Stephan’s quintet and the impact of the collision
Stephan’s Quintet, named after 19th-century French astronomer Édouard Stephan, consists of five galaxies involved in a series of gravitational interactions. In the final collision, NGC 7318b collided with the system, creating a turbulent debris field, according to a Science Live report.
Dr. Marina Arnaudova, an astrophysicist at the University of Hertfordshire, told the publication that the aftermath was “a vast intergalactic field of plasma and gas debris that was re-energized by the collision.” She says this activity has illuminated the plasma at radio frequencies and may have spurred star formation in the region.
Observations and research techniques
The event marked the first use of the WEAVE spectrograph, mounted on the William Herschel telescope in La Palma, Spain. By analyzing the light from the system, researchers tracked debris patterns, ionized gas trails and nascent stars moved by the shock wave. These findings are expected to provide insight into the role of collisions in the formation and evolution of galaxies.
Implications for understanding galactic evolution
The violent encounter within Stephan’s Quintet provides a rare opportunity to observe galaxy collisions in real time. Researchers have indicated that such interactions, which occurred frequently during the universe’s early history, significantly shaped the galaxies we observe today. Although the final outcome of this particular collision may not occur for billions of years, the data collected is expected to advance understanding of the processes associated with galaxy formation and merger.
This research highlights the dynamic and often chaotic nature of the universe, providing astronomers with vital information about the interconnected evolution of stars, galaxies and cosmic phenomena.
