Giant hourglass-shaped bubble discovered inside Milky Way

Astronomers have long discovered large-scale structures of hot gas in the Milky Way. Previously it was thought that they arose after the death of a giant star, but now more accurate data have appeared, indicating a large burst of energy, equal in strength to an explosion of one hundred thousand supernovae.

On the maps of the Northern sky, there is an area called the "northern polar spur". According to traditional science, it arose from a supernova explosion. As it turned out, there is a similar structure in the southern sky, which, together with the previously discovered one, forms a giant bubble resembling Fermi gamma radiation. Visually, it looks like an hourglass located in the middle of the Milky Way.

The new data was obtained by the eROSITA radio telescope, sent into space aboard the Spektr-RG spacecraft on July 13, 2019. The analysis revealed that the galactic bubble is several kiloparsecs (50,000 light-years) across, which corresponds to the borders of the Milky Way. According to astronomers, the structure shows a striking morphological similarity to the "Fermi bubbles" discovered ten years ago in gamma rays.

The scientific community cannot yet explain how such a massive structure could have formed. Presumably, it could have been the result of a black hole burst inside the galaxy. However, this object is currently inactive. It is also noted that the energy required to form bubbles is equivalent to the explosion of one hundred thousand supernovae.

This important discovery will help astronomers understand the cosmic cycle of matter in and around the Milky Way.