The Hubble Space Telescope is famous for taking beautiful images of distant galaxies and nebulae, in some of which you can see stars being born. But this birth can be kick-started by destruction, with the formation of star clusters being supercharged by epic collisions when galaxies smash together.
To celebrate the new year, the Hubble team has released a gallery of six images of such galaxy mergers, where stars are formed in dramatic conditions.
The six mergers pictured here were imaged by Hubble between 2008 and 2020 and show, from left to right, top to bottom: NGC 3256, NGC 1614, NGC 4194 also known as the Medusa merger, NGC 3690, NGC 6052, and NGC 34.
These mergers can create huge clusters of stars. Within our galaxy, you can find star clusters that are 10,000 times the mass of the sun. But in merging galaxies, you can find much larger clusters with a mass of millions of times the mass of the sun. These new clusters can also be very bright, shining out through the cosmos even after the drama of the merger is over.
These mergers were studied in a survey called the Hubble imaging Probe of Extreme Environments and Clusters (HiPEEC) survey, which studies galaxy mergers to learn how they affect star clusters and star formation. The collisions often lead to a dramatic uptick in the rate of star formation, so Hubble observes the systems using ultraviolet and near-infrared wavelengths to peer into the clusters and determine their age, mass, and star formation rate.
These dramatic conditions can be used as a tool to observe star cluster formation in the extremes: “It is during rare merging events that galaxies undergo dramatic changes in their appearance and in their stellar content,” the Hubble scientists write. “These systems are excellent laboratories to trace the formation of star clusters under extreme physical conditions.”
