The Hydra Cluster of Galaxies
Credit & Copyright: David Malin
(AAO),
AATB
Explanation:
The
Hydra Cluster of Galaxies contains well over
100 bright galaxies - but perhaps fewer
galaxies than
might be expected from its mass.
Clusters of galaxies
are the largest gravitationally bound objects in the universe.
Most of a
cluster's mass, however, appears to be in a form
too dark to see, as analyses of the
distribution of X-ray light,
gravitational lensing,
and internal motions indicate.
Abell 1060, as the
above cluster is also known,
appears to have an even higher fraction of
dark matter than seen in a similar cluster, a situation
astronomers cannot easily reconcile
with both clusters forming solely from gravitational attraction.
The Hydra Cluster of Galaxies, named for its
home constellation, spans about ten million
light years.
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.
