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How massive is Vintergatan?

Lead by Ekta Patel, a fourth year graduate at the University of Arizona, the study is the first of its…

Lead by Ekta Patel, a fourth year graduate at the University of Arizona, the study is the first of its kind to use the 3D movements for satellite galaxies and compare their angular momentum in a simulated universe and finally end the Milky Way tipping the waves at 0.96 trillion times the sun pulp. Unlike previous studies that have used the positions and rates of satellite galaxies, this new study uses the lack of network change between the two. Because the angular moment in a system stays constant over time, this new method allows researchers to remove some of the uncertainty that plagues others approaching, paving the way for more reliable results.

“Think of a skier who makes a pirouette,” Patel said in a press release. “As she pulls her arms, she spins faster. In other words, her speed changes, but her angular momentum keeps the same throughout her duration.”

Presented at 232th American Astronomical Society in Denver, the study uses satellite galaxies data from the Hubble Space Telescope. In order to arrive at the 0.96-trilion solar mass estimate, the study compared the angular momentum of nine satellite galaxies to those of a simulated universe of 20,000 galaxies as our own. This comparison helped the chart nine probability distributions – possible values ​​for the values ​​of our galaxy mass – whose ensemble resulted in the estimate of 0.96 trillion solar masses.

“Our method allows us to utilize measurements of the speed of several satellite galaxies at the same time to get a response to what cold dark matter theory would predict the mass of the Milky Way halo in a robust way,” said co-author Gurtina Besla in a press release.

It is not uncommon for researchers to use satellite galaxies to measure the mass of the plant. Since we can not see the entire galaxy, we trust its interactions with nearby galaxies. Winter Street is the proud owner of at least 50 such galaxies – called Local Group – all of which include their own abundance of stars.

But not all of these are well understood. In addition to the Magellanic Clouds, which are clearly visible to the naked eye, all other satellite galaxies are extremely difficult to detect even with telescopes, making it difficult to determine if they exist at all. A satellite galaxy’s brightness is often used to estimate its mass, but the orbital movements do not always follow the results of the previous method. In order to explain this imbalance between what we can detect and the invisible mass of our universe, we turn to the cold dark matter theory.

The theory suggests that dark matter is made from heavy, slow particles that account for about 85% of the universe’s matter. This type of dark matter affects weak interaction with visible matter to form small lumps that are later drawn together to form larger bodies.

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