The Lyman Alpha Forest
Credit & Copyright: J. Shalf, Y. Zhang
(UIUC) et al.,
GCCC
Explanation:
We live in a forest.
Strewn throughout the universe are "trees" of
hydrogen gas that absorb light from distant objects.
These gas clouds leave numerous
absorption lines in a distant
quasar's
spectra, together called the
Lyman-alpha forest. Distant
quasars appear to be absorbed by
many more
Lyman-alpha clouds than nearby quasars,
indicating a Lyman-alpha thicket early in our universe.
The
above image depicts one possible
computer realization of how Lyman-alpha
clouds were distributed at a
redshift of 3. Each side of the box measures
30 million light-years across. Much remains unknown about the
Lyman-alpha forest, including the
real
geometry and extent of the clouds, and
why there are so many fewer clouds today.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
