The universe is full of unexplained celestial wonders, and the "Fermi bubbles" are among them, named after the Fermi gamma-ray telescope, with which they were first discovered in 2010.

These bubbles are huge explosions of high-energy gas emanating from the heart of the Milky Way and extending on either side of it at a length of about 50,000 light-years.

These mysterious purple structures float above and below the center of our galaxy, and despite their impressive size, the mechanism by which they formed has remained a mystery.

There are many theses and hypotheses about the formation of Fermi bubbles, including the explosive activity of the massive central black hole, the winds coming from it and the constant activity of star birth;

Distinguishing between these scenarios is a difficult task, but the availability of the latest X-ray observations from the Suzaku satellite provides an opportunity to compare the measurements with what astronomers expect from the different scenarios.

In a study recently published in the Monthly Notices of the Royal Astronomical Society, according to a press release published on Phys.org on January 3. ;

Professor Yutaka Fujita of Tokyo Metropolitan University-Japan provided theoretical evidence of how such entities form.

highly charged particles

Professor Fujita's simulation considered that the rapidly flowing wind from the black hole injected the necessary energy into the gas surrounding the galactic center;

Compared to the measured shapes, it was found that there is a good probability that the Fermi bubbles were produced by these fast-flowing winds, which have been blowing at 1,000 kilometers per second for 10 million years.

Of course, these winds are not the same as those we see on Earth, but streams of highly charged particles traveling at high speeds spread through space.

According to the press release, this wind travels outwards and interacts with the surrounding gaseous halo. This interaction causes a reverse shock that creates a characteristic elevation in the temperature curve. Fermi bubbles also correspond to the volume inside this reverse shock front.

There are many theses and hypotheses about the formation of Fermi bubbles (Scientific American)

More importantly, however, the simulations show that the instantaneous explosion at the center cannot reproduce the shapes measured by the telescope, tipping the scenario that relies on the steady winds from the central black hole as the cause.

Professor Fujita notes that the winds predicted by the simulation are similar to the outflows observed in other galaxies.

This similarity indicates that the same types of supermassive outflows seen in other parts of the universe are present in our galaxy until recently.