Two exact matches to the Milky Way system have been found by an international astronomer team. The group was led by Dr. Aaron Robotham of the International Center for Radio Astronomy Research (ICRAR) and Scotland's University of St. Andrews.
"We’ve never found another galaxy system like the Milky Way before, which is not surprising considering how hard they are to spot! It’s only recently become possible to do the type of analysis that lets us find similar groups,” said Dr Robotham, lead author of the study's paper, to Sci-News. The find was published in the Monthly Notices of the Royal Astronomical Society (arXiv.org version).
The diligent search for galaxy groups similar to ours was accomplished through high-powered telescopes and a highly-detailed map of the local Universe, the Galaxy and the Mass Assembly survey (GAMA). In other words, everything needed to come together at once for the rare occurrence of the Milky Way twins was where it needed to be. The two exact matches amongst hundreds of thousands of surveyed galaxies is in the low 3% ratio. Few galaxies have large galaxies in orbit around them like the GAMA20267 Magellanic Clouds --- most are small in size.
"We found about 3% of galaxies similar to the Milky Way have companion galaxies like the Magellanic Clouds, which is very rare indeed. In total we found 14 galaxy systems that are similar to ours, with two of those being an almost exact match,” Dr Robotham continued explaining to Sci-News.
ICRAR reports that until the recent find of the twin galaxies, the Milky Way could have been one of a kind. But the ICRAR article, "The Magellanic System: In Perspective," states that the close proximity between the Milky Way and Magellanic Clouds provides ways to study star formation in low metallicity environments, feedback processes in the interstellar medium, and physical roles of galaxy interaction in chemical and dynamical evolution of gas-rich galaxies.This new data provides an open door to further studies of the formation and evolution of galaxies in general and the System.