One of the most stunning images taken by the powerful NASA to date The James Webb Space Telescope is of the Stefan quintamerA group of five galaxies about 290 million light-years away. While the first snapshot released last year was stunning on its own, Webb’s team is also collaborating with other telescopes to reveal new insights into the group — including a catastrophically massive shock wave caused by a collision between galaxies.
Astronomers using observations from Webb together with the Atacama Large Millimeter/submillimeter Array (ALMA) have detected a sonic boom several times larger than the Milky Way, caused by the collision of galaxies in Stephan’s Quintet. The results, presented at an American Astronomical Society press conference on January 9, reveal insights into the gaseous clouds in Stephan’s Quintet along with the possible formation of a new galaxy.
At the heart of the observation is a galaxy dubbed NGC 7318b – which is on a collision course with its sister galaxy, NGC 7318a. However, NGC 7318b also collides with the rest of Stephan’s Quintet, creating massive perturbations in the surrounding clouds of hydrogen gas.
“When this intruder collides with the cluster, it collides with an ancient stream of gas likely from a previous interaction between two other galaxies, and causes a giant shock wave to form,” said Philip Appleton, an infrared astronomer at Caltech. The Processing and Analysis Center and the project’s principal investigator said in a statement.
He explained that the shock wave creates a “highly disordered” layer, creating “unexpected structures” as well as recirculating molecular hydrogen gas. This gas can be used to form stars, and eventually more galaxies.
However, Appleton also adds that the team doesn’t fully understand the science and data behind gas cycles yet. More research is needed in order to discover its underlying mechanisms and effects.
Fortunately, astronomers are more prepared than ever. Now that Webb is in orbit and paired with powerful radio telescopes like ALMA, researchers are armed with the best instruments in history to study distant phenomena occurring in places like Stephan’s Quintet. The team now plans to use the telescope’s spectroscopic arrays in order to study the galaxy cluster’s X-ray signals, providing further insight into the mysterious and chaotic celestial body.
“These new observations gave us some answers, but ultimately showed us how much we don’t know yet,” said Appleton. He later added, “Basically, we’ve got one side of the story. Now it’s time to get the other.”
