A massive galaxy collision, caused by one traveling at the incredible speed of 3.2 million kilometers per hour, has been observed in unprecedented detail William Herschel Telescope 4.2 meters in diameter, located in the Roque de Los Muchachos Observatory on the Canary island of La Palma, one of the most powerful on Earth.
The dramatic impact was observed in Stephan’s Quintet, a nearby galaxy group of five galaxies first spotted nearly 150 years ago. The immensely powerful encounter was similar to the “sonic boom of a fighter plane,” one of the most astonishing phenomena in the universe.
The collision, announced this Friday in the magazine ‘Monthly notices of the Royal Astronomical Society‘. was detected by a team of more than 60 astronomers using the first observations of the new 20 million euro Weave (William Herschel Telescope Enhanced Area Velocity Explorer) wide-field spectrograph.
“Since its discovery in 1877, the Stephan Quintet has fascinated astronomers because it represents a galactic crossroads where past collisions between galaxies have left behind a complex debris field,” said lead researcher Marina Arnaudova of the University of Hertfordshire.
“Dynamic activity in this group of galaxies was awakened by a galaxy crashing into it at an incredible speed of over 3.2 million km/h, causing an immensely powerful shock, just like the sonic boom of a fighter plane.” summarizes.
Supersonic speeds
The international team discovered a dual nature behind the shock front, previously unknown to astronomers. ”As the shock wave moves through pockets of cold gas, it travels at hypersonic speeds (several times the speed of sound in the intergalactic medium of Stephan’s Quintet), powerful enough to separate electrons from atoms, leaving behind a bright trail of charged gas, as seen with Weave,” he noted. Arnaudova.
However, when the shock wave passes through the surrounding hot gas, it becomes much weaker, according to PhD student Soumyadeep Das, from the University of Hertfordshire. “Rather than causing a significant disturbance, the weak shock compresses the hot gas, producing radio waves that are captured by radio telescopes such as the Low Frequency Array (LOFAR),” he added.
For Gavin Dalton, Weave’s principal investigator at the University of Oxford, “it’s fantastic to see the level of detail uncovered.” In his opinion, “in addition to the ongoing crash and collision details that we see in Stephan’s Quintet, these observations provide remarkable insight into what might be happening in the formation and evolution of the faint, newly resolved galaxies that we see in the limits of our current capabilities.
“I am excited to see that the data collected in Weave’s first light already provide an impactful result, and I am confident that this is just a first example of the kind of discoveries that will be possible with Weave on the William Herschel Telescope in the coming years,” said Marc Balcells, director of the Isaac Newton Telescope Group.
What are the key implications of studying galaxy collisions like those observed in Stephan’s Quintet?
Interview: Exploring the Dramatic Collision of Galaxies with Marina Arnaudova
Time.news Editor (TNE): Welcome, Marina! It’s a pleasure to have you with us today. Your recent work on the galaxy collision has drawn significant attention. Can you start by giving us a brief overview of what you and your team observed?
Marina Arnaudova (MA): Thank you for having me! We recently observed a dramatic collision within Stephan’s Quintet, a galaxy group that has intrigued astronomers since it was first spotted in 1877. During our study, we detected a galaxy traveling at an incredible speed of over 3.2 million kilometers per hour, resulting in a powerful shock akin to the sonic boom of a fighter jet. This collision has allowed us to witness the dynamic activity and complex debris field left by previous galactic encounters.
TNE: It’s truly astonishing! What makes the Stephan’s Quintet so important in the study of galaxy interactions?
MA: Stephan’s Quintet serves as a unique laboratory for understanding the effects of galactic collisions. Because of its history of gravitational interactions, we can study the remnants of past collisions and explore how they influence the formation and evolution of galaxies. Our observations have revealed new insights into the shock front generated by these interactions, showcasing a dual nature that had not been recognized before.
TNE: The use of the William Herschel Telescope and the new WEAVE spectrograph sounds intriguing. How did these tools enhance your research?
MA: The William Herschel Telescope is one of the most powerful telescopes on Earth, and it enabled us to capture unprecedented detail of the collision. The new WEAVE spectrograph, which is a €20 million project, provided us with wide-field spectroscopic observations, allowing us to analyze the speed and composition of the galaxies involved in real-time. This technology is crucial for deciphering the complex dynamics at play in such violent cosmic events.
TNE: You mentioned a previously unknown dual nature to the shock front. Could you elaborate on that discovery?
MA: Certainly! The dual nature of the shock front refers to the different physical phenomena occurring as a result of the collision. We found that there are varying shock wave strengths that impact how energy is distributed across the galaxies involved. This discovery opens up new avenues for understanding the mechanisms by which galaxies interact and evolve after a collision, contributing to our broader knowledge of the universe’s dynamics.
TNE: That’s fascinating! In light of these findings, what future research do you foresee for your team and other astronomers working in this area?
MA: We’re excited about the possibility of further observations to better understand the implications of such high-speed collisions. Our work encourages collaborative studies across various telescopes and observational techniques to create a holistic picture of galaxy formation and interaction. Additionally, we hope to engage more deeply with the public and academia to share the wonders of these cosmic events.
TNE: Thank you for sharing your insights, Marina. It’s amazing how the study of galactic collisions not only enhances our understanding of the universe but also ignites public interest in astronomy. We look forward to hearing more from you and your team in the future!
MA: Thank you! It’s been a pleasure discussing our research, and I hope to inspire others to look up at the night sky with curiosity.