New Delhi: The James Webb Space Telescope and the Hubble Space Telescope have both captured a pair of interacting galaxies designated as IC 2163 on the left that is creeping behind the larger NGC 2207 on the right. The gravitational interactions between the two galaxies have caused both of them to deform, stretching out their spiral arms, and causing the formation of tidal trails. Both the interacting galaxies are producing new stars at a furious rate, producing about two dozen stars similar to the Sun every year. Such a star is produced by the Milky Way only about six to seven stars every year for comparison.
Hubble image on the left and the Webb image on the right. (Image Credit: NASA, ESA, CSA, STScI).
Astronomers have also recorded seven supernovae in the colliding galaxies in recent years, which is also a much higher rate than the Milky Way, where a supernova explosion occurs about once every 50 years. The spiral galaxies have spiral arms that contain bright stars, interspersed by dark lanes of gas and dust, that make up the raw material from which new stars are born. These regions are obscured in optical frequencies, but the sensitive infrared gaze of Webb can reveal the skeletons of galaxies, providing scientists with a window to study their underlying structure.
The future of the two galaxies
The fate of the interacting galaxies are not known. Such interactions encourage the process of star formation, but also depletes the reservoirs of star forming material available within a galaxy, causing them to age faster. Over many millions of years, the galaxies may disentangle and depart from each other, resulting in tidal tails that may even bridge the two galaxies. It is also possible that the cores and the arms of the two galaxies will meld, with the two galaxies coalescing into one. Either way, the star formation is expected to slow down as the gas and dust from the galaxies are depleted.
