Around the Milky Way there is a small old dwarf galaxy called Tukana II, which has a big secret. According to a new study of stars orbiting an object, it is far from it, Dark matter The sphere of influence is much larger than we thought.
In fact, it’s huge. Although Tucana II’s stars are 3,000 times more massive than the Sun, the dark matter’s have a crown mass 10 million times that of the Sun. This is three or five times more than the previous estimate.
This suggests that the first galaxies in the universe may be much larger than we know them to be.
“Tucana II has much more mass than we thought to connect these distant stars.” Annot Chittis, an astronomer at the Massachusetts Institute of Technology. “That means the other remaining first galaxies are likely to have such long halls.”
The milk root has a section The whole set Companion dwarf galaxies. These are small and fragile clusters of stars with very small minerals, revealing that they are very old, because the minerals took some time to form in the hearts of the stars and spread throughout the universe.
About 163,000 light-years from Earth, Tucana II is the smallest. Based on the percentage of minerals in its stars, it is one of the oldest because it has almost no minerals. Chet and his team searched for the stars in hopes of finding an old group of stars.
They made the notes through the Australian National University Skymapper The telescope and the results were performed using an algorithm developed by Kitty to select poor mineral stars. In addition to the stars in the Tucana II kernel, the algorithm found nine new stars far away.
This was confirmed by data collected by Gia Satellite, a three-dimensional Milky Way mapping project, including stellar motion. Those stars that are so far away from the nucleus of the dwarf galaxy revolve around gravity.
However, the previously calculated galaxy did not contain the mass needed to create a gravitational force connecting these distant stars. This means that there is a mass that we cannot see or find directly. This means dark matter.
We do not know what dark matter is, but there is an invisible mass in the universe responsible for creating all the extra gravity, the rapid rotation of galaxies, and the curvature of space – time. It is a dark substance, the glue that binds galaxies together.
Without dark matter, galaxies would be much farther away. Chitty Tika. “[Dark matter] A critical factor in the formation of the galaxy and its integration. “
Based on the positions of the stars and their motions, the team was able to update the Tucana II Dark Metal Mass Estimate, which eventually reached the 10 million solar range. This is the first evidence that ultra-bright dwarf galaxies contain a lot of dark matter, which creates a lot of secrets.
“This means that the first galaxies formed halos of dark matter that are much larger than previously thought.” Said astronomer Anna Freebela From the Massachusetts Institute of Technology. “We thought the first galaxies were small and weak galaxies. But in reality, they may be many times larger than we thought, and they were not very small.”
So where does all this dark matter come from? Evidence of this may be in the stars in the galaxy. When the team from Magellan Telescope in Chile studied the data, they found that not all stars have the same mineral.
In fact, they are sharply divided into two groups. The stars on the periphery of Tucana 2 contained three times more minerals than the stars in the center, indicating two different groups. In the Milky Way, this can happen if a group of stars come from another place, for example, colliding with another galaxy.
This is the first time an ancient galaxy has seen such a chemical difference between stars, but the reasons are probably the same: At one time, Tucana II was not a single galaxy, but a halo of dark matter merging into two galaxies.
“Let’s witness the signature of the first cannibal in the galaxy,” Freebells said. “The galaxy may have swallowed up one of its smaller and more primitive neighbors, who carried all of its stars to the periphery.”
However, studies have shown that a wide range of these small space galaxies can now be observed and distinguished from others, such as Tucana II. There are even two candidates – the ultra-clear dwarf galaxy Seg1, boots, and each star is far from the core of the galaxy.
The team plans to use its technology to locate and explore these stars and many more galaxies.
“There may be many other systems, and perhaps these stars are shining on their fringes.” Freebells said.
The study was published Natural astronomy.