From observations taken by the Hubble Space Telescope, we learned that the most likely path to produce the different types of galaxies we observe in our close universe is by mergers of galaxies. Examples of these mergers are plentiful, and with each of them, we learn interesting aspects of these interactions. The enigmatic cosmic collision of the galaxy pair IC1623 is a great example. Observed by Hubble in 2002 and later in 2008, we got a detailed view of this pair of luminous infrared galaxies that lies around 275 million light-years away in the constellation of Cetus (the Whale). This year, the James Webb Space Telescope provided another view, shedding more light on the processes triggered by the union of the galaxies.
While Hubble’s images reveal intricate regions of star formation next to several dark and dusty clouds, the interacting galaxy system glows with spectacular magnificence in the infrared wavelengths. Using three instruments, Webb took images of the thick band of dust and unveiled, with impressive detail, a trident of star formation connecting the two galaxies and centered in a fan-like cloud of cold dust and gas produced during the early-stage merger, after the first passage. At the fan’s rivet point, the reaction of the gas, probably when the disks first overlapped, seems to have set off a more powerful burst of star formation and given rise to a compact starburst galaxy.
Astronomers propose that the merging galaxies may well be in the process of forming a supermassive black hole at the center of the luminous core – seen at the bottom of the image taken by Webb. This core is so bright and compact that it produces diffraction spikes in the images, where the 8-pronged, snowflake-like diffraction spikes are created by the interaction of starlight with the physical structure of the telescope.
For the images refer to
JWST: https://esawebb.org/images/potm2210a/