Campus: San Francisco State University -- January 30, 2004
SFSU Uncovers Surprises In The Stars
According to conventional wisdom, the universe's galaxies have evolved
slowly over time, as stars and groups of stars collide and merge into
increasingly larger groupings. But new observations by the Gemini Deep
Deep Survey (GDDS) team reveal large, mature galaxies when the universe
was only 3-6 billion years old, much earlier than such galaxies were
believed to have existed.
Ron Marzke, SFSU assistant professor of astronomy, is a member of the
eight-organization multinational GDDS team that made the discovery,
which challenges the "hierarchical" or building blocks theory
of galaxy evolution. The findings were announced Jan. 5 at the 203rd
meeting of the American Astronomical Society, and covered by The New
York Times, Space.com,
Today and others.
The team focused on a relatively unexplored period of the universe known
as the "Redshift Desert," looking back to an era just a few
billion years after the Big Bang. Spectra from more than 300 galaxies
were collected, and because the team used a special technique to capture
the faintest galactic light ever dissected into color spectra, this
is the first sampling to include not just galaxies with bright young
stars, but a range of normal, dimmer and more massive galaxies.
"It gives us a much less biased picture of what was in place when
the universe was 3-6 billion years old," Marzke said.
The team could efficiently focus on the most promising and representative
sampling of about 300 galaxies because of an earlier survey that was
processed at SFSU and the Carnegie Observatories. Marzke was a co-principal
investigator of the earlier Las Campanas Infrared Survey, a detailed
and time-consuming process of detecting about 100,000 galaxies. The
Las Campanas survey employed a unique approach toward astronomical observation.
Rather than wait for much-sought-after time on one of the largest telescopes
in the field, Marzke and colleagues pooled their time on 2.5- and 4-meter
telescopes, achieving "big telescope science" by using lots
of time on relatively smaller telescopes. Marzke led the processing
of the survey's optical data using a powerful computing center made
possible by the support of SFSU's College of Science and Engineering.
Other institutions on the GDDS team are: University of Toronto, Johns
Hopkins University, Carnegie Institution of Washington, Herzberg Institute
of Astrophysics, Gemini Observatory, Oxford University and Massachusetts
Institute of Technology. The observations were conducted using the Frederick
C. Gillett Gemini North Telescope located on Mauna Kea, Hawaii.
Ligeia Polidora, 415/338-3053, firstname.lastname@example.org