Seen in detail a galactic collision at millions of kilometers per hour

Nov. 22 () –

A telescope has seen in unprecedented detail a massive collision of galaxies caused by one of them traveling at an incredible speed of 3.2 million kilometers per hour.

The dramatic impact was observed in the Stephan Quinteta nearby galaxy group made up of five galaxies that It was first sighted almost 150 years ago.

It caused an immensely powerful shock similar to a “sonic boom of a fighter jet”, one of the most surprising phenomena in the Universe, according to astronomers who have witnessed the event.

Stephan’s Quintet represents “a galactic crossroads “where past collisions between galaxies have left behind a complex debris field,” which has now been awakened by the passing galaxy NGC 7318b.

The collision was detected by a team of scientists using the first observations from the new wide-field spectrograph WEAVE (William Herschel Telescope Enhanced Area Velocity Explorer), on the Canary Island of La Palma.

This cutting-edge scientific facility will not only reveal how our Milky Way galaxy was built over billions of years, but will also provide new insights into millions of other galaxies across the Universe.

The discovery of NGC 7318b colliding with Stephan’s Quintet was observed by a team of more than 60 astronomers and has been published in Monthly Notices of the Royal Astronomical Society.

The system is an ideal laboratory for understanding the chaotic and often violent relationship between galaxies, which is why it was the focus of the first observation by WEAVE’s Large Integral Field Unit (LIFU).

Lead researcher Dr Marina Arnaudova, from the University of Hertfordshire, said in a statement: “Since its discovery in 1877, the Stephan Quintet has captivated astronomers because it represents a galactic crossroads where past collisions between galaxies have left behind a complex debris field.

“Dynamic activity in this group of galaxies has now been awakened by a galaxy crashing into it at an incredible speed of more than 2 million mph (3.2 million km/h), “which causes an immensely powerful crash, much like the sonic boom of a fighter jet.”

The international team has discovered a dual nature behind the shock front, previously unknown to astronomers.

“As the shock 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 glowing trail of charged gasas seen with WEAVE,” Dr. Arnaudova said.

However, when the shock passes through the surrounding hot gas, it becomes much weaker, according to PhD student Soumyadeep Das, from the University of Hertfordshire.

He added: “Rather than causing significant disruption, weak shock compresses hot gaswhich gives rise to radio waves that are captured by radio telescopes such as the Low Frequency Array (LOFAR)”.

The new information and unprecedented details come from WEAVE’s LIFU, which combines data with other cutting-edge instruments such as LOFAR, the Very Large Array (VLA), and the James Webb Space Telescope (JWST).

WEAVE is a next-generation superfast mapping device that has been connected to the William Herschel telescope to analyze the composition of stars and gas in both the Milky Way and distant galaxies.

This is done with the help of a spectroscope, which reveals the elements that make up the stars by generating a barcode-style pattern. inside a prism of colors that form a light source.

It was designed and built following a multilateral agreement between France, Italy and the countries of the Isaac Newton telescope group (United Kingdom, Spain and the Netherlands).

Astronomers hope WEAVE will help reveal how our galaxy formed in unprecedented detail and revolutionize our understanding of the Universe.

Professor Gavin Dalton, WEAVE Principal Investigator at RAL Space and the University of Oxford, said: “It’s fantastic to see the level of detail discovered here by WEAVE.

“In addition to the details of the shock and collision we see in Stephan’s Quintet, these observations provide remarkable insight into what may be happening in the formation and evolution of the faint, barely resolved galaxies we see at the limits of our current capabilities.” “.