Giant Cosmic Cloud Larger Than Milky Way Found in Leo Cluster

Astronomers find a gas cloud 10 billion times the Sun’s mass, drifting in space.

Key Takeaways

1. A massive gas cloud, larger than the Milky Way, was found in the Leo Cluster.
2. The cloud, likely stripped from a galaxy, has stayed intact for hundreds of millions of years.
3. Magnetic fields are believed to help the cloud resist diffusion in the cluster’s hot gas medium.
4. Its discovery offers insights into how galaxy clusters interact and how galaxies lose their gas.
5. This finding may lead to the identification of similar clouds and improve understanding of cluster dynamics.

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A Cosmic Cloud Bigger Than the Milky Way

In a groundbreaking discovery, astronomers detected a colossal gas cloud drifting within the Leo Cluster (Abell 1367), located 300 million light-years away. This gas cloud is larger than the Milky Way and weighs 10 billion times the mass of the Sun. Using data from the ESA’s XMM-Newton X-ray telescope, Subaru Telescope, and the MUSE instrument on the Very Large Telescope, researchers confirmed the cloud’s extraordinary size and unique properties.

The cloud emits X-rays and glows faintly in the H-alpha spectral line, consistent with temperatures between 10,000 and 10,000,000 Kelvin. These characteristics align with gas found in galaxies but not the hotter gas (100 million Kelvin) of the intracluster medium. Scientists hypothesize that the cloud was stripped from a galaxy by ram pressure as the galaxy moved through the cluster at speeds of 1,000–2,000 kilometers per second.

An Enigmatic Survival

What makes this discovery remarkable is that the cloud has persisted for hundreds of millions of years without diffusing into the surrounding intracluster medium. Researchers propose that a magnetic field is stabilizing the gas, keeping it clumped together despite external forces.

The parent galaxy from which the cloud was torn is yet to be identified, but clues such as the cloud’s high mass and potential gas trails may help pinpoint its origin. This finding is the first of its kind, offering direct evidence that intracluster gas can strip galaxies of their material, forming long-lasting clouds.

Looking ahead, astronomers believe this discovery could pave the way for identifying more such clouds. This, in turn, will deepen our understanding of galaxy clusters, intracluster dynamics, and how matter is distributed in the universe.