Iowa State, IBM Astronomers Explain Why Disk Galaxies Eventually Look Alike
It happens to all kinds of flat, disk galaxies – whether they’re big, little, isolated or crowded in a cluster. They all grow out of their irregular, clumped appearance and their older stars take on the same smooth look, predictably fading from a bright center to a dim edge.
Or, as Curtis Struck, an Iowa State University astronomer, wrote in a research summary: “In galaxy disks, the scars of a rough childhood, and adolescent blemishes, all smooth away with time.”
But how does that happen?
Struck, a professor of physics and astronomy who studies galaxy evolution and wrote the 2011 book “Galaxy Collisions,” said a few explanations have been proposed, but most of those only covered certain types of galaxies. There hasn’t been an explanation for the nearly universal and exponential fade in the brightness of the lookalike disk galaxies.
Full Story: http://www.news.iastate.edu/news/2013/09/11/galaxyevolution