For more than 30 years, the Milky Way galaxy – the center of the Milky Way, home to billions of stars – has been shrinking, researchers say. Now researchers at Oxford University and University College London (UCL) They finally test.
In a new study, Posted in Monthly Announcements of the Royal Astronomical Society, Researchers have used the European Space Agency’s (ESA) Kia telescope to observe a large group of stars called the Hercules Stream, which orbits the center of the Milky Way at the same speed as the galaxy. As the speed of the bar decreases, the stars move away.
The stars in the rotating bar are trapped in gravity, and the asteroids in the asteroid belt follow Jupiter’s orbit. Experts have discovered that stars carry a “chemical fingerprint”. This element comes in the form of heavy metals, which show that stars have moved away from the center of the galaxy, which is rich in stars and gases.
Using this data, the team found that the bar, which is made up of billions of stars and trillions of solar masses, has reduced its rotation by at least 24% since its formation.
Measurement of the new type of dark matter
Researchers say it provides a new kind of insight into the nature of dark matter, which acts as a counterweight to reduce rotation.
“The opposite weight reducing this rotation must be a dark matter. Until now, we have only been able to infer the dark matter by mapping the gravitational pull of galaxies and subtracting the contribution of visible matter,” said Dr. Ralph Schonrich, co-author of the study. “Our research offers a new type of measurement of dark matter: not its gravitational energy, but its passive mass (dynamic response), which reduces the rotation of the rod,” he said.
According to the UCL Press, the Milky Way, like other galaxies, is believed to be submerged in a “halo” of dark matter. The dark matter is invisible and its nature is unknown, but its existence is inferred from galaxies, which act as if they were covered much larger than we can see. It is believed that there is about five times darker matter in the universe than normal visible matter.
Alternative theories of gravity, such as the modified Newtonian dynamics, reject the concept of dark matter and attempt to explain the contradictions by modifying Einstein’s general theory of relativity.
Some (UCL, New Scientist, Monthly Announcements of the Royal Astronomical Society)