Arp 107: James Webb reveals cosmic collision in stunning clarity
The James Webb Space Telescope captured an image of a collision between a spiral galaxy and an elliptical galaxy. Together, they form a system known as Arp 107. Although the object had been studied before, it is only now that it has been photographed with such high resolution.
3:16 PM EDT, September 21, 2024
Arp 107 is a system of galaxies located in the constellation Leo Minor, approximately 450 million light-years away from Earth. The Spitzer Space Telescope observed it in 2005. Thanks to the James Webb Telescope, a much more detailed image has been obtained with a previously unattainable resolution.
Astronomers created a composition of images obtained from two cameras operating in the mid-infrared and near-infrared—MIRI and NIRCam. NIRCam perfectly shows stars within both galaxies and reveals their connection—a translucent, white bridge composed of stars and gas being pulled by both galaxies. MIRI, rendered in red-orange hues, reveals regions where new stars form and dust composed of organic molecules—polycyclic aromatic hydrocarbons.
The MIRI camera also revealed the core of the large spiral galaxy with a supermassive black hole at the center, which, in its current form, looks a bit like a smiling face. The spiral galaxy belongs to the so-called Seyfert galaxies, characterized by a very bright core. The source of this extraordinarily bright light is most likely the matter falling into the central black hole.
The Arp 107 system resembles the famous Cartwheel Galaxy—one of the first interacting galaxy systems observed by the James Webb Telescope. According to the Polish Press Agency, Arp 107 may have looked very similar to the Cartwheel Galaxy. However, the smaller elliptical galaxy likely collided from the side rather than a direct hit, causing the spiral galaxy to avoid significant destruction. Only its arms were disturbed.
Galaxy collisions do not necessarily mean something bad. They can facilitate star formation by compressing gas, improving the conditions necessary for their formation. On the other hand, as observed by Webb, such collisions also scatter a lot of gas. This, in turn, can deprive new stars of the material needed for their formation.
The James Webb Space Telescope recorded the Arp 107 galaxies during the merging process, which can last for hundreds of millions of years. As scientists predict, when the galaxies rebuild after the chaos caused by the collision, the system may lose its "smile." At the same time, it may transform into something interesting and worthy of future astronomers' attention.
