UCLA astronomy graduate student Ryan Sanders discovered a way to precisely measure oxygen in distant galaxies like COSMOS-1908, indicated by the arrow. Credit: Ryan Sanders and the CANDELS team
UCLA astronomers have made the first accurate measurement of the abundance of oxygen in a distant galaxy. Oxygen, the third-most abundant chemical element in the universe, is created inside stars and released into interstellar gas when stars die. Quantifying the amount of oxygen is key to understanding how matter cycles in and out of galaxies.
This research is published online in the Astrophysical Journal Letters, and is based on data collected at the W. M. Keck Observatory on Mauna Kea, in Hawaii.
“This is by far the most distant galaxy for which the oxygen abundance has actually been measured,” said Alice Shapley, a UCLA professor of astronomy, and co-author of the study. “We’re looking back in time at this galaxy as it appeared 12 billion years ago.”
Knowing the abundance of oxygen in the galaxy called COSMOS-1908 is an important stepping stone toward allowing astronomers to better understand the population of faint, distant galaxies observed when the universe was only a few billion years old and galaxy evolution, Shapley said.