A belief that has existed for a long time milk wayThe galaxy, which includes the Earth and the solar system, is relatively static, broken by a new cosmic concept.
The spiral disk of stars and planets is pulled, bent, and deformed by the gravitational force of a smaller galaxy, the Great Magellanic Cloud (LMC).
Scientists believe that the LMC crossed the Milky Way border about 700 million years ago, according to cosmological standards, and seriously disrupted the texture and movement of our galaxy due to its large content of dark matter.
Astronomers say that the effects are still being felt today and that we need to reconsider how our galaxy evolved.
The LMC, now a satellite galaxy of the Milky Way, appears as a faint cloud in the night skies of the southern hemisphere – of the same name, 16in Ferdinand Magellan, the Portuguese explorer of the century.
Previous research has shown that LMC is surrounded by a halo, a dark substance like the Milky Way – that surrounds galaxies and does not receive or emit light, but has a dramatic gravitational effect on the motion of stars and gas in the universe.
Using an advanced statistical model that calculates the speed of the Milky Way’s most distant stars, the University of Edinburgh team has discovered how the LMC disrupts the motion of our galaxy. The work was published in Natural Astronomy, Funded by the British Council for the Establishment of Science and Technology (STFC).
The researchers found that the giant gravity of LMC’s dark matter halo drove the Milky Way disc at 32 km / h, or 115,200 kilometers per hour toward Pegasus.
Surprisingly, they found that the Milky Way was moving toward a point in its former trajectory, not the LMC’s current location as previously thought.
The reason for this is that the LMC, which is strengthened by mass gravity, is moving away from the Milky Way at a speed of 370 km / h, 1.3 million kilometers per hour.
Astronomers say that it is as if the Milky Way is trying hard to hit a fast-moving target, but it is not getting a very good target.
This discovery will help scientists develop new modeling techniques that reflect the strong dynamic interactions between the two galaxies.
Astronomers now intend to study the direction in which the LMC first landed on the Milky Way and the exact time it occurred. This will reveal the amount and distribution of dark matter in the Milky Way and LMC in an unprecedented detail.
Leading author of the Faculty of Physics and Astronomy and Member of Postdoctoral Research Dr. Michael Petersen said:
“Our findings ask for new Milky Way models to describe the evolution of our galaxy.
“We created a background in which stars at incredibly large distances of 300,000 light-years preserved a memory of the Milky Way structure before the LMC landed, and we measured a star disk flying in space. Pulled by the gravitational force of the LMC. ”
Jorge Peñarrubia, Professor of the Private Department of Gravitational Dynamics, Faculty of Physics and Astronomy, said:
“This discovery definitely breaks the magic of our galaxy being in a kind of equilibrium,” he said. In fact, the recent decline of the LMC is causing serious concern over the Milky Way.
“Understanding this can give us an unparalleled idea of the distribution of dark matter in both galaxies.”
Reference: “Detection of Milky Way reflex action due to the fall of the Great Magellanic Cloud” by Michael S. Petersen and Jorge Peñarrubia, November 23, 2020, Natural Astronomy.
DOI: 10.1038 / s41550-020-01254-3