Acceleration relation found among spiral and irregular galaxies challenges current understanding of dark matter
Wednesday, September 21, 2016 - 08:31
in Astronomy & Space
In the late 1970s, astronomers Vera Rubin and Albert Bosma independently found that spiral galaxies rotate at a nearly constant speed: the velocity of stars and gas inside a galaxy does not decrease with radius, as one would expect from Newton's laws and the distribution of visible matter, but remains approximately constant. Such 'flat rotation curves' are generally attributed to invisible, dark matter surrounding galaxies and providing additional gravitational attraction.