Failed galaxy

Cloud-9 was discovered three years ago as part of a radio survey by the Five-hundred-meter Aperture Spherical Telescope (FAST) in Guizhou, China, a finding later confirmed by the Green Bank Telescope and the Very Large Array facilities in the United States. Unlike in Western hemisphere culture, the moniker 'Cloud-9' has no significance for the Chinese. It was simply named sequentially, having been the ninth gas cloud identified on the outskirts of a nearby spiral galaxy, Messier 94 (M94).

The cloud is close to M94 and appears to have a physical association with the galaxy. High-resolution radio data shows slight gas distortions, possibly indicating interaction between the cloud and galaxy.

Cloud-9 may eventually form a galaxy in the future, depending on if it grows more massive. If it were much bigger, it would have collapsed, formed stars, and become a galaxy that would be no different than any other galaxy we see. If it were much smaller, the gas could have been dispersed and ionized and there wouldn’t be much left. But it’s in a sweet spot where it could also still remain as a RELHIC.

This finding furthers the understanding of galaxy formation, the early Universe, and the nature of dark matter itself. The lack of stars in this object provides a unique window into the intrinsic properties of dark matter clouds. The rarity of such objects and the potential for future surveys is expected to enhance the discovery of more of these 'failed galaxies' or 'relics,' resulting in insights into the early Universe and the physics of dark matter.

This result has been published in The Astrophysical Journal Letters.