Madrid, 30 years (Europe Press)
Galactic collisions are transformative events, largely responsible for driving the evolution of the universe. The mixing and matching of stellar material is an incredibly dynamic process that can lead to the formation of newly formed star-populated molecular clouds. But in the case of the so-called “Candy Galaxies”, a different type of structure is presented.
Although this intergalactic bridge is filled with star-forming material, its turbulent nature prevents star formation.
This pair of galaxies is located about 180 million light-years away, in the direction of the Pegasus constellation, NOIRLab reports.
This new image, taken with the Gemini North telescope, operated by NOIRLab, shows the cool feature that gave them their name. A faint bridge of tight molecular filaments, in brown, and clumps of hydrogen gas, shown in red, can be seen between the two galaxies. Its intricate network structure is like a candy bar that expands as the pair slowly separate.
Galaxy collisions can occur in a variety of different scenarios, often involving a larger galaxy and a smaller satellite galaxy. As they get closer together, the satellite galaxy may pull on one of the larger galaxy’s primary spiral arms, throwing it out of its orbit. Or the satellite galaxy may intersect with the larger galaxy, causing significant distortions in its structure. In other cases, a collision can lead to merging if none of the members have enough momentum to continue after the collision.
In all of these scenarios, stellar matter from both galaxies is mixed through gradual mixing and redistribution of gas, like two pools of liquid slowly oozing into each other. The gathering of gas and its resulting compression can lead to the formation of stars.
However, a head-on collision would be more like pouring liquid from two separate glasses into a common container. When the candy galaxies collided, their galactic discs and gas components collided with each other. This injected huge amounts of energy into the gas, making it very turbulent. As the pair emerged from their collision, gas was pulled at high speeds from each galaxy, creating a huge gas bridge between them. The turbulence of stellar material throughout the bridge now prevents the aggregation and compression of gas required to form new stars.
Gemini North’s observations of this object were led by Analia Smith-Castelli, an astronomer at the La Plata Institute in Argentina. .