Free Astronomy Magazine November-December 2024

NOVEMBER-DECEMBER 2024 represented in orange-red, shows star-forming regions and dust that is composed of soot-like organic molecules known as polycyclic aro- matic hydrocarbons. MIRI also pro- vides a snapshot of the bright nu- cleus of the large spiral, home to a supermassive black hole. The spiral galaxy is classified as a Seyfert galaxy, one of the two largest groups of active galaxies, along with galaxies that host quasars. Seyfert galaxies aren’t as luminous and distant as quasars, making them a more convenient way to study similar phenomena in lower energy light, like infrared. This galaxy pair is similar to the Cartwheel Galaxy, one of the first interacting galaxies that Webb ob- served. Arp 107 may have turned out very similar in appearance to the Cartwheel, but since the smaller elliptical galaxy likely had an off- center collision instead of a direct hit, the spiral galaxy got away with only its spiral arms being dis- turbed. The collision isn’t as bad as it sounds. Although there was star formation occurring before, colli- sions between galaxies can com- press gas, improving the conditions needed for more stars to form. On the other hand, as Webb reveals, collisions also disperse a lot of gas, potentially depriving new stars of the material they need to form. Webb has captured these galaxies in the process of merging, which will take hundreds of millions of years. As the two galaxies rebuild after the chaos of their collision, Arp 107 may lose its smile, but it will inevitably turn into something just as inter- esting for future astronomers to study. Arp 107 is located 465 million light-years from Earth in the con- stellation Leo Minor. !