Astronomers find seven dwarf-galaxy groups, the building blocks of massive galaxies
Dwarf galaxies, nuggets of stars and gas 100 to 1,000 times smaller than the Milky Way, are thought to be the building blocks of massive galaxies. Evidence for groups of merging dwarf galaxies, however, has been lacking, until now.
"We know that to make a large galaxy, the universe has to bring together many smaller galaxies," said Sabrina Stierwalt an astronomer with the National Radio Astronomy Observatory (NRAO) and University of Virginia in Charlottesville. "For the first time, we have found examples of the first steps in this process -- entire populations of dwarf galaxies that are all bound together in the same general neighborhoods."
The researchers then used the Magellan telescope in Chile, the Apache Point Observatory in New Mexico, and the Gemini telescope in Hawaii to confirm that the apparent clusters are not just on the same line of sight but are also approximately the same distance from Earth, indicating they are gravitationally bound together.
|Four of the dwarf galaxies [Credit: Kelsey E Johnson, Sandra E Liss, and Sabrina Stierwalt]|
"We hope this discovery will enable future studies of groups of dwarf galaxies and offer insights into the formation of galaxies like the Milky Way," concluded Stierwalt.
Source: National Radio Astronomy Observatory [January 23, 2017]