Our galaxy is pushed through the Universe at 630 km per second

Our galaxy, the Milky Way, moves in time with the expanding Universe at 630 km per second. But what still was unclear was what is propelling us through space.

Scientists had assumed a dense region of the Universe called the Great Attractor, made of clusters of galaxies 150 million light-years from the Milky Way, was pulling the galaxy through space. 

Israeli researchers are now suggesting that a large intergalactic void is actually pushing us through space. The article has been published at Nature Astronomy magazine.

It reports the discovery of a practically empty region in our galactic neighbourhood, which is pushing our galaxies out into space. To find the void, the researchers started looking at the motion of all galaxies.

Credit: Yehuda Hoffman, Daniel Pomarede, R. Brent Tully, Helene Courtois.

Researchers created a map of the galaxy flow field and used this to infer the underlying distribution of stars and dark matter. The came to the conclusion that there are overdense areas pulling on the Milky Way and an understarred region that’s pushing it.

“Through 3D 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 Dr. Yehuda Hoffman of Hebrew University's Racah Institute of Physics.

“It has become apparent that push and pull are of comparable importance at our location”.

The ‘Dipole Repeller’ explains both the direction of the Milky Way’s motion and its velocity relative to the rest of the Universe.

The team hopes that future ultra-sensitive surveys at optical, near-infrared and radio wavelengths will be able to directly identify the small few galaxies in the void and confirm its discovery.

Watch this video to learn more about the research: