We need a light source: a distant galaxy that is bright all over, not just at its core or in a knot of newly formed stars. (newscientist.com)
Without a significant source of heat, the most massive galaxies in the universe would be forming stars at extreme rates that far exceed observations. (sciencedaily.com)
This led researchers to conclude there might be a continuous increase in the efficiency depending on how high above the rate of forming stars is from the main sequence. (alma-telescope.jp)