Washington: Researchers have found that the Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24-light-years across.
York University Physics and Astronomy Professor Marshall McCall maps out bright galaxies within 35-million light-years of the Earth, offering up an expanded picture of what lies beyond our doorstep.
McCall said that all bright galaxies within 20 million light-years, including us, are organized in a `Local Sheet` 34-million light-years across and only 1.5-million light-years thick.
McCall says twelve of the fourteen giants in the Local Sheet, including the Milky Way and Andromeda, are "spiral galaxies" which have highly flattened disks in which stars are forming.
The remaining two are more puffy "elliptical galaxies," whose stellar bulks were laid down long ago. Intriguingly, the two ellipticals sit on opposite sides of the Council.
Winds expelled in the earliest phases of their development might have shepherded gas towards the Local Group, thereby helping to build the disks of the Milky Way and Andromeda .
The study has been published in the Monthly Notices of the Royal Astronomical Society.