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Credit & Copyright: N. Benitez (JHU),
T. Broadhurst (Hebrew Univ.),
H. Ford (JHU),
M. Clampin (STScI),
G. Hartig (STScI), G. Illingworth (UCO/Lick), ACS Science Team, ESA, NASA
Explanation:
Two billion
light-years away, galaxy cluster Abell 1689 is
one of the most massive objects in the Universe.
In
this view from the Hubble Space Telescope's
Advanced Camera for Surveys,
Abell 1689 is seen to warp space as predicted by
Einstein's
theory of gravity -- bending light
from individual galaxies which lie
behind the cluster to produce multiple, curved images.
The power of this enormous
gravitational lens depends on its mass, but
the visible matter,
in the form of the cluster's yellowish galaxies, only accounts
for about one percent of the mass needed to make the observed
bluish arcing images of background galaxies.
In fact, most of the gravitational mass required
to
warp space enough to explain this cosmic scale lensing is in the
form of still mysterious
dark matter.
As the dominant source of the cluster's gravity,
the dark matter's
unseen presence is mapped out
by the lensed arcs and
distorted
background galaxy images.
G. Hartig (STScI), G. Illingworth (UCO/Lick), ACS Science Team, ESA, NASA
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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: abell 1689
Publications with words: abell 1689
See also: