Traditionally, the center of our galaxy is supermassive black hole. The “huge” part isn’t just a superlative. A typical black hole formed from the explosive death of a star weighs a few dozen times the mass of the Sun, but a supermassive black hole, like Sagittarius A* in the Milky Way, weighs about 4 million times the mass of our star.

But new research challenges this long-held idea. Instead of a black hole, there may be something else lurking there that observers cannot see. It is a huge mass of dark matter that is thought to make up 85 percent of the total mass of the universe.

a new researchpublished in a magazine Royal Astronomical Society Monthly Noticesclaims This would be possible if dark matter were actually made of elementary particles called fermions. Compared to conventional dark matter, which forms more diffuse clumps or “halos,” fermion dark matter is thought to be pushed together to form more tightly packed nuclei.

Although dark matter is a cornerstone of modern cosmology, it remains a hypothesis. Its existence was deduced after astronomers realized that given the speed at which galaxies rotate, the ordinary visible matter they contain does not exert enough gravitational force to hold the galaxies together. In their model, dark matter provides the gravitational glue that keeps these vast regions from flying apart.

Perhaps dark matter could even form the centers of galaxies. The researchers found that by replacing Sgr A* with a clump of fermions, they recreated the direct gravitational effects of a black hole, including the orbits of fast-moving stars near the center of the galaxy called S stars, which fly at speeds of thousands of kilometers per second.

In addition, dark matter theory could explain another galactic phenomenon: why stars on the outskirts of the Milky Way appear to slow down (called Keplerian attenuation). Researchers believe this is due to a dense dark matter core. The vast halo of dark matter It spans the galaxy.

“We’re not just replacing black holes with dark objects; we’re proposing that supermassive centers and galactic dark matter halos are two manifestations of the same continuum of matter,” co-author Carlos Arguelles of the La Plata Institute for Astrophysics said in the paper. advertising slogan About work.

But what about the groundbreaking photos of Sagittarius A* taken by the Event Horizon Telescope? Researchers claim that a glowing accretion disk of hot material swirling around the galactic center could cast shadows similar to those seen in the images.

“Dense dark matter cores can mimic shadows because they bend light very strongly, creating a central darkness surrounded by bright rings,” lead author Valentina Crespi from the La Plata Institute of Astrophysics said in the paper.

This is a provocative theory, but it is not yet convincing enough to overturn the black hole consensus. But future observations looking for evidence of significant black holes may ultimately prove the astronomers right.

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