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Credit & Copyright: NASA,
ESA,
Hubble;
Processing & Copyright:
Rogelio Bernal Andreo
(DeepSkyColors.com)
Explanation:
What are those strange arcs?
While imaging the cluster of galaxies Abell 370,
astronomers noticed an unusual arc.
The arc wasn't understood right away --
not until better images showed that the arc was
a previously unseen type of
astrophysical artifact of a
gravitational lens,
where the lens was the center of an entire
cluster of galaxies.
Today, we know that this
arc,
the brightest arc in the cluster, actually consists of
two distorted images of a fairly normal galaxy that
happens to lie far in the distance.
Abell 370's
gravity caused the background galaxies' light -- and others -- to
spread out and come to the observer along
multiple paths, not unlike a distant light appears through the stem of a
wine glass.
Almost all of the yellow images
featured here are galaxies in the Abell 370 cluster.
An astute eye can pick up many
strange arcs and
distorted arclets, however,
that are actually
gravitationally lensed
images of
distant normal galaxies.
Studying Abell 370
and its images gives astronomers a unique window into the distribution of normal
and
dark
matter in
galaxy clusters and the universe.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: galaxy cluster - gravitational lens
Publications with words: galaxy cluster - gravitational lens
See also: