 |
| Most
distant quasar—redshift 5
(the faint red dot at the arrow.) |
An unassuming speck of red light
assumed gargantuan proportions in
2000, when scientists at the Sloan
Digital Sky Survey used detection
and computational techniques borrowed
from particle physics to find the
most distant object ever observed.
This quasar had the highest redshift
ever seen, corresponding to a distance
of 27 billion light years from Earth.
Redshift (meaning the light appears
shifted to the red end of the spectrum)
is used as a measure of the distance
of celestial objects. Because the
universe is expanding, the quasar
was only about 4 billion light years
from Earth when the light seen now
was emitted-at a time when the universe
was very young, less than 1 billion
years old. Quasars are compact, luminous
objects believed to be the high-energy
nuclei of young galaxies. Finding
distant quasars is a specialty of
the Sky Survey, launched in 2000 as
the most ambitious astronomical survey
ever. It will exceed all predecessors
in scale, mapping in detail one-quarter
of the entire sky and producing more
sensitive and accurate images than
ever made before by using electronic
light detectors instead of photographic
techniques. The project involves 11
universities and other institutions,
including Fermi National Accelerator
Laboratory. The telescopes are located
in New Mexico.
Scientific Impact:
The Sky Survey is producing a field
guide to the universe that will be
used by scientists for decades to
come. It will have a significant impact
on astronomical studies ranging from
the origin and evolution of galaxies
to the properties and distribution
of the dust from which stars like
the sun were created.
Social Impact: The
Sky Survey is extending the practice
of mapmaking—laying the gridwork
for reality—to cosmography, the
science of mapping the universe and
determining the place of humans in
it. It will enhance 100-fold humans'
three-dimensional picture of the universe,
producing a quantity of information
rivaling the content of the Library
of Congress.
Reference: "The
Discovery of a Luminous z=5.80 Quasar
from the Sloan Digital Sky Survey,"
X. Fan et al., to be published in
Astron. Journal.
URL:
http://www.sdss.org/science/
Technical Contact:
Prof. Michael Turner, mturner@oddjob.uchicago.edu
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of High Energy and Nuclear
Physics |
