Institute for Astronomy | University of Hawaii | 2017 Jan 30
For decades, astronomers have known that our Milky Way galaxy - along with our companion galaxy, Andromeda - is moving through space at about 1.4 million miles per hour with respect to the expanding universe. Scientists generally assumed that dense regions of the universe, populated with an excess of galaxies, are pulling us in the same way that gravity made Newton's apple fall toward earth.Click to play embedded YouTube video.
In a groundbreaking study published in Nature Astronomy, a team of researchers, including Brent Tully from the University of Hawaii Institute for Astronomy, reports the discovery of a previously unknown, nearly empty region in our extragalactic neighborhood. Largely devoid of galaxies, this void effectively exerts a repelling force, pushing our Local Group of galaxies through space.
Astronomers initially attributed the Milky Way's motion to the Great Attractor, a region of a half-dozen rich clusters of galaxies 150 million light-years away. Soon after, attention was drawn to a much larger structure called the Shapley Concentration, located 600 million light-years away, in the same direction as the Great Attractor. However, there has been ongoing debate about the relative importance of these two attractors and whether they suffice to explain our motion. ...
The Dipole Repeller - Yehuda Hoffman et al
- Nature Astronomy 1:0036 (30 Jan 2017) DOI: 10.1038/s41550-016-0036
