NASA’s Webb once again took a look at galactic collisions.

Arp 107 (NIRCam and MIRI Image).

This composite image of Arp 107, captured by the James Webb Space Telescope’s NIRCam and MIRI, reveals insights into star formation and the collision of these two galaxies hundreds of millions of years ago.

Smile for the camera! The interaction between the elliptical galaxy and the spiral galaxy, known as Arp 107, creates a striking visual reminiscent of a happy face, complete with bright “eyes” and a wide semicircular “smile.” This region was previously observed in infrared by NASA’s Spitzer Space Telescope in 2005, but the James Webb Space Telescope offers much higher resolution. 

The image is a composite of data from Webb’s MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera). NIRCam highlights the stars in both galaxies and reveals a translucent bridge of stars and gas connecting them, formed during their encounter. MIRI data, shown in orange-red, identifies star-forming regions and dust made up of polycyclic aromatic hydrocarbons. It also captures the bright nucleus of the spiral galaxy, home to a supermassive black hole.

Arp 107 (MIRI Image).

This image of Arp 107, captured by Webb’s MIRI, reveals the supermassive black hole at the center of the large spiral galaxy on the right, with dust lanes drawn in by its gravitational pull. The black hole also displays Webb’s characteristic diffraction spikes, resulting from light interacting with the telescope’s structure.

The spiral galaxy in Arp 107 is classified as a Seyfert galaxy, part of a major group of active galaxies alongside those hosting quasars. Seyfert galaxies are less luminous and more accessible for study in lower energy light, such as infrared. 

This galaxy pair is reminiscent of the Cartwheel Galaxy, one of Webb’s earliest observations of interacting galaxies. While Arp 107 could have resembled the Cartwheel, the smaller elliptical galaxy likely experienced an off-center collision, resulting in only minor disturbances to the spiral arms.

Despite the collision’s implications, it can actually enhance star formation by compressing gas, creating better conditions for new stars to emerge. However, as Webb’s observations show, such interactions can also disperse gas, potentially limiting the materials available for future star formation.

Webb has captured Arp 107 during its merging process, which will unfold over hundreds of millions of years. As the galaxies recover from their collision, Arp 107 may lose its distinct appearance, but it will evolve into something equally fascinating for future astronomers. Located 465 million light-years from Earth in the constellation Leo Minor, Arp 107 continues to intrigue scientists.