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Астронет: Астрономическая картинка дня Самая далекая галактика в фокусе скопления галактик http://variable-stars.ru/db/msg/1196555/eng |
Credit & Copyright: ESA,
NASA,
J.-P. Kneib
(Caltech/Observatoire Midi-Pyrenees)
&
R. Ellis
(Caltech)
Explanation:
Gravity can bend light, allowing whole clusters of galaxies
to act as huge telescopes.
Almost all of the bright objects in this just-released
Hubble Space Telescope image are galaxies in the
cluster known as
Abell 2218.
The cluster is so massive and so compact that its
gravity bends and focuses the light
from galaxies that lie behind it.
As a result,
multiple images of these background
galaxies are distorted into long faint arcs -
a simple lensing effect analogous to viewing distant street
lamps through a glass of
wine.
The cluster of galaxies
Abell 2218 is itself about two billion
light-years away in the northern constellation
Draco.
The power of this massive cluster telescope has
recently allowed astronomers to detect a galaxy at a
redshift of about 7, the
most distant galaxy or quasar
yet measured.
Three images of this young, still-maturing galaxy are
faintly visible in the white contours near the image
top and the lower right.
The recorded light, further analyzed with a
Keck Telescope, left this galaxy
when the universe was only about five percent of its
current age.
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.