A Year of Resolving Backgrounds
Credit:
The MAXIMA Collaboration,
NSF
No matter which direction you look,
no matter what type of light you see,
the sky glows - but why?
The sources of many of these
background radiations have remained long-standing puzzles,
but this millennial year brought some partial resolutions.
In X-ray light the recently launched spacecraft
Chandra and
XMM
resolved much of the seemingly uniform
X-ray background into many discrete sources, many of which appear to be
black holes at the centers of galaxies
accreting matter.
In
microwave light, the
BOOMERANG and
MAXIMA-1 missions
resolved with
new clarity
the seemingly uniform
microwave background.
The size and distribution of these
spots indicates a
geometrically flat universe,
which, when combined recent
supernovae results,
indicate a universe with an accelerating expansion rate
filled with
dark matter and
dark energy.
Pictured above, a map spanning ten degrees of the
microwave sky resolves the
microwave background
into hot and cold spots, as indicated in microkelvins.