Scientists have discovered that a hot sphere surrounds the Milky Way, with temperatures reaching 10 million degrees Celsius.

Scientists have determined that the Milky Way is surrounded by a vast sphere of hot gas, and they have also found an explanation for how this structure exists. In other words, astronomers have identified a mysterious source that directs heat from our galaxy into its surroundings. The research has been published in The Astrophysical Journal, reports Phys.

The Milky Way is composed of hundreds of billions of stars, but there is significantly more interstellar gas necessary for the formation of new stars. Accurately estimating the volume of this gas has proven difficult, given that it is quite sparse.

Several decades ago, astronomers first discovered that the Milky Way is surrounded by a massive sphere of hot gas. The diameter of this sphere is estimated to be about 700,000 light-years, which is seven times larger than the size of the Milky Way. Scientists found that the temperature of this gas is several million degrees Celsius.

Now, astronomers have discovered even hotter gas within this sphere, with a temperature of 10 million degrees Celsius. However, the source of heat necessary to maintain such a temperature was initially undetected. Astronomers continued their investigation and uncovered what it could be.

Signs of the existence of super-hot gas around our galaxy were detected through the X-ray radiation it emits. At the same time, indications of this gas were found in the spectra of light emitted by three distant quasars (very bright cores of distant galaxies created by massive black holes) in the form of an absorbing medium.

The study revealed that the gas responsible for emission and absorption is not the same substance. Only the very hot gas surrounding the Milky Way emits X-ray light.

Scientists concluded that explosions of massive stars in various regions of the galactic disk, manifested as supernovae, heat the gas around the disk to extremely high temperatures. In the process, they enrich the matter surrounding our galaxy with heavy chemical elements created during the explosion.

The gas produced during stellar explosions moves out of the galactic disk and bursts into the surrounding cosmos, heating the local intergalactic gas, and then cools down, possibly returning back to the galaxy.

A significant amount of chemical elements such as sulfur, magnesium, and neon has been found in the very hot gas surrounding our galaxy. These elements are ejected into space during supernova explosions.

Scientists believe that the combination of massive star explosions and active star formation has also contributed to the existence of the very hot gas sphere around our galaxy.