A Galactic Oddity with a Central Mystery

“Everything about this galaxy is unusual,” said the researcher. “It not only has a bizarre appearance, but it also hosts a supermassive black hole consuming a significant amount of material. The biggest surprise? The black hole isn’t located in either of the two galactic nuclei from the merger—it sits right in the middle. We kept asking ourselves: how can we make sense of this?”

Figure 1. “‘Infinity’ Galaxy Mystifies Astronomers”.

Van Dokkum and astronomer Gabriel Brammer of the University of Copenhagen first spotted this oddity while analyzing images from the COSMOS-Web survey, part of NASA’s James Webb Space Telescope data archives. Figure 1 shows “‘Infinity’ Galaxy Mystifies Astronomers”.

Follow-up observations of the Webb data drew on measurements from the National Radio Astronomy Observatory’s Very Large Array, the Chandra X-ray Observatory, and the Keck Observatory. These multi-wavelength observations were critical in interpreting the mysterious galaxy.

Using Keck’s Low-Resolution Imaging Spectrometer (LRIS), van Dokkum and his team obtained spectra that revealed essential information: the distance to the Infinity galaxy, the precise location of its newly formed black hole, and its mass—roughly a million times that of the Sun, comparable to the Milky Way’s central black hole.

“This is a prime example of Keck Observatory’s pivotal role in following up on unusual objects spotted in JWST images,” said van Dokkum. “The flexibility of Keck’s observing model allows astronomers to decide in real time what to observe, enabling rapid pursuit of high-risk, high-reward targets that fixed-schedule observatories cannot accommodate. The Keck/Yale partnership has been crucial for this and many other discoveries, and this pipeline will only strengthen with Roman and future advanced Keck instruments.”

Black Hole Formation: A Tale of Two Seed Theories

Discovering a black hole outside a galaxy’s nucleus is rare in itself, but finding one that has only just formed is unprecedented. This discovery also bears on ongoing debates about how black holes formed in the early universe.

The “light seeds” theory suggests that black holes began as remnants of massive stars that collapsed and exploded, gradually merging over time to form supermassive black holes. However, JWST has already detected supermassive black holes at epochs too early for the light seed model to fully explain.

An alternative, the “heavy seeds” theory, posits that massive black holes can form directly from the collapse of enormous gas clouds. The challenge is that such clouds usually form stars rather than black holes.

Van Dokkum proposes that the Infinity galaxy may demonstrate how extreme conditions—similar to those in the early universe, as suggested by the heavy seeds model—can create a black hole.

“In this case, two disk galaxies collided, forming the ring-like structures we observe,” he explained. “During the collision, gas in the galaxies was shocked and compressed. This compression could create a dense knot that collapses directly into a black hole. While such collisions are rare today, extreme gas densities were likely common in the early universe when galaxies were forming.”

Van Dokkum emphasized the need for further research. “We want to get closer to the black hole to study the gas in its immediate vicinity,” he said. “Later this fall, we will use Keck Observatory’s adaptive optics for this investigation.”

“Beyond that,” he added, “the ball is in the theorists’ court. We need computer simulations to test whether extreme conditions during collisions can indeed form black holes. In a galaxy unimaginably far away, the universe just created a black hole—and in doing so, it offered a clue about how our own Milky Way was born.”

Source: SciTECHDaily

Cite this article:

Priyadharshini S (2025), Strange ‘Infinity’ Galaxy Baffles Scientists: How Do We Make Sense of It?, AnaTechMaz, pp.482