Abell 3827: Cannibal Cluster Gravitational Lens
Explanation:
Is that one galaxy or three?
Toward the right of the
featured Hubble image of the massive galaxy cluster Abell 3827
is what appears to be a most unusual galaxy -- curved and with three centers.
A detailed analysis, however, finds that these are three images
of the same background galaxy -- and that there are at least four more images.
Light we see from the single background blue galaxy takes
multiple paths through the complex gravity of the cluster,
just like a single distant light can take multiple paths
through the stem of a wine glass.
Studying how clusters like Abell 3827 and their component
galaxies deflect distant light gives
information about how mass and
dark matter are distributed.
Abell 3827 is so distant, having a
redshift of 0.1, that the light we see from it
left about 1.3 billion years ago -- before
dinosaurs roamed the Earth.
Therefore,
the cluster's central galaxies
have now surely all coalesced -- in a feast of
galactic cannibalism -- into
one huge galaxy near the cluster's center.
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.
