Council of Giants
Map showing the Council of Giants Marshall McCall / York University

Planet Earth sits among a "Council of Giants", according to a map showing the galaxies lying near the Milky Way.

Marshall McCall, from the York University Physics & Astronomy, has mapped out the bright galaxies lying in the area 35 million light years from Earth, giving a clearer picture of what lies beyond the Milky Way and Andromeda – our galaxy's closest neighbour.

"All bright galaxies within 20 million light years, including us, are organised in a 'Local Sheet' 34-million light years across and only 1.5-million light years thick," he said.

"The Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24 million light years across – this 'Council of Giants' stands in gravitational judgment of the Local Group by restricting its range of influence."

Published in the Monthly Notices of the Royal Astronomical Society, McCall explains how 12 of the 14 galaxies, including the Milky Way and Andromeda, are spiral galaxies, with flattened disks in which stars form.

The other two are "puffy" galaxies, with stellar bulks created long ago. Both these galaxies sit at opposite sides of the Council, he adds.

Council of Giants
Side view showing the map of the Council Marshall McCall / York University

Explaining how the galaxies in the Council move, he said: "Thinking of a galaxy as a screw in a piece of wood, the direction of spin can be described as the direction the screw would move (in or out) if it were turned the same way as the galaxy rotates.

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"Unexpectedly, the spin directions of Council giants are arranged around a small circle on the sky. This unusual alignment might have been set up by gravitational torques imposed by the Milky Way and Andromeda when the universe was smaller."

Researchers believe the latest map showing the Council of Giants offers a look at the conditions that led to the formation of the Milky Way.

They believe just a small increase in the density of matter was needed to create the Milky Way and Andromeda, as to create such an orderly arrangement, galaxies must have developed with a pre-existing sheet-like foundation.

McCall said: "Recent surveys of the more distant universe have revealed that galaxies lie in sheets and filaments with large regions of empty space called voids in between. The geometry is like that of a sponge. What the new map reveals is that structure akin to that seen on large scales extends down to the smallest."