Empty Region in the Universe Responsible for Pushing Away Milky Way Through Space
A new study has revealed that the previously unknown, nearly empty region in space is responsible for the expansion of the universe, pushing away the Milky Way and other local galaxies through space.
The study, published in the journal Nature Astronomy, showed that the so-called Dipole Repeller acts as a repellant force pushing away the galaxies in the Laniakea Supercluster, which includes our very own Milky Way and the Andromeda galaxy, towards the direction of the Great Attractor and Shapley Concentration.
"Through 3-d mapping the flow of galaxies through space, we found that our Milky Way galaxy is speeding away from a large, previously unidentified, region of low density that we call the Dipole Repeller, as well as towards the known Shapley Concentration," said lead researcher, Yehuda Hoffman, from the Hebrew University's Racah Institutes of Physics, in a press release. "It has become apparent that push and pull are of comparable importance at our location."
The Great Attractor is a region in the universe about 150 million light-years away and contains around half a dozen cluster of galaxies. In the same direction of the Great Attractor about 600 million light-years away lies the larger Shapley Concentration. Previous theories in the expansion of the universe suggest that the Great Attractor and Shapley Concentration are pulling the galaxies towards their direction.
For the study, the researchers developed a three-dimensional map of the galaxy flow field. The researchers then used the 3-D map to infer the underlying distribution of stars and dark matter.
The researchers found that galaxies tend to be pulled towards the more crowded area of the universe, such as the Great Attractor and Shapley Concentration, away from the nearly empty regions of space like the Dipole Repeller.
The researchers noted that the universe is full of attractors and repellers. However, repellers and the galaxies within them are currently understudied. This is due to the fact that repellers have low density, making them appear as dark, empty voids.