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Simulations provide clue to missing planets mystery 14 hours ago. Nov 11, We know that galaxy rotation is happening because the Milky Way is a flattened disk, in the same way that the Solar System is a flattened disk. The centrifugal force from the rotation flattens out the galactic disk.
All stars in the galactic disk follow roughly circular orbits around the center of the galaxy. Stars in the halo can have much different orbits and speeds. The calculation of the high rotational speed of the galaxy led to the discovery of dark matter. Our result is helping us to understand how that galactic rotation builds up across cosmic time.
The research has early access availability in the journal Monthly Notices of the Royal Astronomical Society MNRS and is also available in full on the preprint site arxiv. Tech Explorist publishes the latest researches and discoveries in science, health, the environment, technology, and more from leading universities, scientific journals, and research organizations.
What causes the rotation of galaxies? Sky survey provides clues to how they change over time. By Amit Malewar. Astronomer Vera Rubin pioneered work on galaxy rotation rates, showing that spiral galaxies rotate faster than if their gravity were solely due to the constituent stars and gas.
An additional, invisible substance known as dark matter must influence galaxy rotation. A spiral galaxy of a given mass in stars is expected to rotate at a certain speed. Super spirals also reside in larger than average dark matter halos. The most massive halo that Ogle measured contains enough dark matter to weigh at least 40 trillion times as much as our Sun. That amount of dark matter would normally contain a group of galaxies rather than a single galaxy. The fact that super spirals break the usual relationship between galaxy mass in stars and rotation rate is a new piece of evidence against an alternative theory of gravity known as Modified Newtonian Dynamics, or MOND.
MOND proposes that on the largest scales like galaxies and galaxy clusters, gravity is slightly stronger than would be predicted by Newton or Einstein.
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