Pasadena Star-News
NASA discovers dozens of galaxies
Ultraviolet detectors used to find new stars
By Kimm Groshong
Staff Writer
Tuesday, December 21, 2004 - LA CANADA FLINTRIDGE -- A long- sought-after Holy Grail for astronomers is a complete understanding of how galaxies such as the Milky Way formed.
But since scientists believe most of the formative steps took place more than 10 billion years ago, directly observing that process by looking at galaxies more than 10 billion light years away is pushing the scope of modern technologies.
At least that was the case until recently when NASA's Galaxy Evolution Explorer, also known as GALEX, discovered what appears to be three dozen "newborn galaxies' much closer to Earth than any of those older galaxies.
The newborns are only about 100 million to one billion years old, scientists said during a teleconference from the Jet Propulsion Laboratory on Tuesday.
"These galaxies give us a great opportunity to study the processes that give birth to galaxies in an up-close-and-personal way,' said Tim Heckman, the leader of the study from Johns Hopkins University. "It's almost like looking out the window and seeing a dinosaur walking by.'
The Galaxy Evolution Explorer mission, launched in April 2003, is designed to complete the first survey of the sky in ultraviolet light in order to study how the universe came to contain the stars, galaxies and clusters of galaxies that currently exist.
Since young galaxies produce new stars at a rate about 100 times faster than normal, GALEX can locate them by looking in wide areas of space for exceptionally bright areas in the ultraviolet.
Caltech leads the GALEX mission and is responsible for its science operations and data analysis. JPL manages the mission for NASA.
"These newborn galaxies are near us but they are very rare,' said Chris Martin, a Caltech physics professor and the principal investigator for Galex. "In a single image, we might see many thousands of galaxies ... and one of these is one of these new galaxies,' he said.
Numerous problems hinder astronomers' observations of older galaxies. "We can't obtain detailed information because these newborn galaxies in the early universe are faint and small and also because observations at certain wavelengths are just not possible at such great distances,' said Alice Shapley, an astronomer from UC Berkeley.
But she said the newborns may actually represent the same type of building blocks that formed the Milky Way. "The GALEX sample is so close by that we can obtain exquisitely detailed information from it about the processes that are involved in star and galaxy formation,' she said.
Shapley added that the project of gathering such additional detailed information about the galaxies' compositions and structures would be an ideal job for the Hubble Space Telescope.
Heckman noted that the group's data is "quite incomplete' since the discovery is so new. "We would very much like to get get more information about these galaxies,' he said. Another possibility is a combination of GALEX's observations with those from the Spitzer Space Telescope, which tracks heat rather than ultraviolet light.
Kimm Groshong can be reached at (626) 578-6300, Ext. 4451, or by e-mail at kimm.groshong@sgvn.com .
From nothing comes everything. Just think. were all star dust from type II Supernovas.
From one of the biggest bangs comes us! If that don’t describe Genesis I don’t know what could.
There was that thread the other day. About that atheist after looking at the Universe. Said there must be a guiding intelligence.