Big Isle scopes see
universe expand
By David Briscoe Astronomers using telescopes atop Hawaii's Mauna Kea are helping take the most precise measurements yet of faraway galaxies forming flurries of stars when the universe was just a couple of billion years old.
Associated PressUsing telescopes as time machines, scientists are watching the universe unfold as light, at various wavelengths, reaches Earth billions of years after the stars were formed.
Because of the time it takes the light to reach Earth, the sophisticated instruments attached to the world's most powerful telescopes have been able to record events in 10 faraway galaxies when the universe was less than half its current age of 14 billion years.
The most distant sightings date back 12 billion years, according to astronomers Scott Chapman and Andrew Blain, of the California Institute of Technology, along with British scientists Ian Smail and Rob Ivison, who reported their work in Thursday's issue of the journal Nature.
The measurements of the highly luminous galaxies could reveal more about the most dramatic period of star buildup yet seen in the Milky Way and nearby galaxies, the scientists said.
The camera that first spotted the faraway galaxies in 1997 by recording submillimeter radiation, at wavelengths between that of visible light and radio waves, was attached to the James Clerk Maxwell Telescope atop Mauna Kea on the Big Island.
The new results, however, combine that data with the work of several scientific instruments, including an array of radio telescopes in New Mexico and one of the 10-meter W.M. Keck Observatory telescopes on Mauna Kea.
According to the Nature report, the Keck telescope found the faint spectral signature of radiation that was emitted from the galaxies, at "a single ultraviolet wavelength of 0.1215 micrometers, by hydrogen gas excited by either a large number of hot young stars or by the energy released as matter spirals into a black hole at the core of a galaxy."
Now that the distances of the galaxies are known, other measurements can be taken to provide details of their power source and to predict what the galaxies will look like when the intense activity ends, the scientists said.
W.M. Keck Observatory