UH astronomer wins award for women
Strong stellar winds can blow the oxygen out of galaxies, but this didn't happen to Earth's galaxy, says a University of Hawaii astronomer.
"It's a good thing for us," said Lisa J. Kewley, honored by the American Astronomical Society with a prestigious award for her contributions to astronomy.
A postdoctoral researcher and Hubble Fellow at the UH Institute for Astronomy, Kewley studies oxygen in galaxies to look back in time at the universe.
"Oxygen can get thrown out of galaxies by very strong stellar winds," she said in an interview. "In larger galaxies, this is what happens, but fortunately our galaxy didn't have strong stellar winds."
Consequently, earthlings could be breathing oxygen atoms "anywhere from 5 to 12 billion years old," she said. "It's hard to imagine oxygen being that old, but it certainly is."
Kewley has received the 2006 Annie Jump Cannon Award in Astronomy, presented annually for outstanding contributions to astronomy by a woman within five years of earning a doctorate degree.
Kewley, who was born and raised in South Australia, received the Australian Academy of Science Young Researcher Award in 2000. She was awarded her Ph.D. in 2002 from the Australian National University.
She was at the Harvard-Smithsonian Center for Astrophysics before joining UH a year ago.
She is looking at the spectrum of light from galaxies at different distances from Earth and at different ages, using optical and infrared data from Keck Observatory telescopes on Mauna Kea.
She can figure out from the spectrum of each galaxy how much oxygen it had when it emitted the light billions of years ago.
Comparing the galaxies at different distances "tells us how our galaxy came to look the way it does and how we come to have as much oxygen as we have in our galaxy," Kewley said.
Her findings indicate there was "a burst of oxygen production in the first 6 billion years of the universe." It tapered off but has increased steadily since, although not at the extreme rate of the early years, she said.
"It has to do with star formation," she explained. When the universe was very young, galaxies were closer together and gravity effects caused a lot of star formation with more hot young stars producing oxygen, she said.
Stars still are being formed, but not as much as during the early years of the universe, she said. Also, a lot of galaxies have become quiescent, she said.