For centuries, astronomers have been working to learn more about the Milky Way galaxy. And yet there are still many things that remain incomprehensible to science, for example, determining the exact mass of the galaxy.
This definition is important for understanding the history of the formation of galaxies and the evolution of our Universe. Astronomers have tried various methods to measure the true mass of the Milky Way, but so far none of these methods have been particularly successful.
However, a new study by a group of researchers at the Harvard-Smithsonian Center for Astrophysics has offered a new and interesting way to determine the mass of the Milky Way. Using super-velocity stars (HVS) ejected from the center of the galaxy, they managed to take a step in that direction.
Their study, called Constraining Milky Way Mass with Hypervelocity Stars, was recently published in the journal Astronomy and Astrophysics. The study was prepared by Giacomo Fragione, an astrophysicist at the University of Rome, and Professor Abraham Loeb of Harvard University.
Current estimates of the total mass of the galaxy allowed only rough estimates to be obtained, which ranged from one to several trillion solar masses.
According to Abraham Loeb, their Milky Way model is a laboratory for testing scientists' calculations. This model shows that the number of satellite galaxies in the Milky Way depends on its mass.
Therefore, to study them, scientists decided to use a new approach, which included modeling the motions of super-fast stars to determine the mass of our galaxy.
Pictured: Artistic depiction of a super-fast star that escaped the Milky Way
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Recall that more than 20 such stars have been discovered in our galaxy so far, which move at speeds of up to 700 km / s and are located at a distance of 100 to 50,000 light years from the center of the galaxy.
These stars are believed to be ejected from the center of our galaxy through interactions with a supermassive black hole (SMBH) at the center of our galaxy.
Photo: Accelerating stars in the galaxy
Photo: Distribution of dark matter when the universe was about 3 billion years old, obtained from numerical modeling of the formation of galaxies
As a result of the work done, scientists were able to obtain data that the mass of the Milky Way is in the range of 1.2-1.9 trillion solar masses, Loeb said. While this figure is still imprecise, this latest estimate is a significant improvement over previous estimates.