Astronomers have discovered the first evidence of a dwarf galaxy collision, adding weight and substance to two cosmological theories that have been long talked about before.
The study of cosmology has often observed pairs of large and medium-sized galaxies colliding and merging in times before. Nevertheless, they are different from the dwarf galaxies. These galaxies often linger along the fringes of larger galaxies, whose gravity strips them of their stars before merging takes place.
Sabrina Stierwalt and colleagues from the National Radio Astronomy Observatory in Charlottesville, Virginia, have puzzled out the Sloan Digital Sky Survey and found seven isolated clusters containing nothing but dwarf galaxies. Each group seemed tightly packed and dense enough that at least one pair in each group is predicted to merge, ultimately.
The survey brings into reminder Elena's predicament in 2009. Elena D'Onghia from the University of Wisconsin, Madison, said that we should be able to observe clusters of dwarf galaxies all on their own, even near our galaxy unless gravity is doing something very strange in manipulating the view.
"Based on dark matter theory, we expect a lot of little dwarf galaxies and clumps of dark matter in and around the Milky Way," she mentioned. If so, why has it been challenging to spot these clusters?
The answer is explained by the notion that dwarf galaxies merge to form bigger galaxies like the Milky Way, which leaves only a few to survive nearby. Looking into the times of early universe, it wouldn't be surprising to find that dwarf galaxies could have been many in number but too faint to see.
Mike Boylan-Kolchin at the University of Texas, Austin made a remark pertaining the findings. "Seeing these seven clusters fairly nearby suggests our theories of how galaxies form via collisions are right. It also suggests invisible dark matter is distributed much as we thought - in small patches throughout the universe."
He added saying, "Without the gravity of dark matter haloes, dwarf galaxies wouldn't be able to hold together." As technology advances, researchers hope to see more of these faint clusters coming into view.
