SANTA CRUZ, Calif., March 7 (UPI) -- U.S. astronomers have developed a unifying principle to describe all galaxies, from orderly spirals to chaotic mergers, with mathematical precision.
University of California-Santa Cruz scientists found the relationship between a galaxy's mass and the orbital speed of its stars and gas is consistent over a wide range of galaxy morphologies and over billions of years of galaxy evolution.
The researchers, using results from a major survey of distant galaxies, found certain fundamental properties of galaxies changed little during the past 8 billion years -- about half the age of the universe.
"We think this trend reflects a regularity in the process that led to the formation of galaxies," said astronomy and astrophysics Professor Sandra Faber. "We are not sure where it comes from but it is a major constraint on galaxy formation."
Faber, along with postdoctoral researcher Susan Kassin, determined the more massive a galaxy is, the faster the stars and gas within it move. They discovered the relationship by analyzing data from ground-based and space-based telescopes for 544 distant galaxies with a range of morphologies.
The complex research is to be published in Astrophysical Journal Letters.
