Hubble's Sweeping View of the Coma Cluster of Galaxies
06.10.08
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Release No.: STScI-PRC08-24
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Acknowledgment: M. Carter (Liverpool John Moores University) and the Coma HST ACS Treasury Team
NASA's Hubble Space Telescope captures the magnificent starry population
of the Coma Cluster of Galaxies, one of the densest known galaxy
collections in the universe.
The Hubble's Advanced Camera for Surveys viewed a large portion of the
cluster, spanning several million light-years across. The entire cluster
contains thousands of galaxies in a spherical shape more than 20 million
light-years in diameter.
Also known as "Abell 1656," the Coma Cluster is more than 300 million
light-years away. The cluster, named after its parent constellation Coma
Berenices, is near the Milky Way's north pole. This places the Coma
Cluster in an area unobscured by dust and gas from the plane of the
Milky Way, and easily visible by Earth viewers.
Most of the galaxies that inhabit the central portion of the Coma
Cluster are ellipticals. These featureless "fuzz-balls" are pale goldish
brown in color and contain populations of old stars. Both dwarf, as well
as giant ellipticals, are found in abundance in the Coma Cluster.
Farther out from the center of the cluster are several spiral galaxies.
These galaxies have clouds of cold gas that are giving birth to new
stars. Spiral arms and dust lanes "accessorize" these bright
bluish-white galaxies that show a distinctive disk structure.
In between the ellipticals and spirals is a morphological class of
objects known as S0 (S-zero) galaxies. They are made up of older stars
and show little evidence of recent star formation, however, they do show
some assemblage of structure -- perhaps a bar or a ring, which may give
rise to a more disk-like feature.
This Hubble image consists of a section of the cluster that is roughly
one-third of the way out from the center of the cluster. One bright
spiral galaxy is visible in the upper left of the image. It is
distinctly brighter and bluer than galaxies surrounding it. A series of
dusty spiral arms appears reddish brown against the whiter disk of the
galaxy, and gives rise to the idea that this galaxy has been disturbed
at some point in the past. The other galaxies in the image are either
elliptical, S0 galaxies, or background galaxies far beyond the Coma
Cluster sphere.
The data of the Coma Cluster were taken as part of a survey of a nearby
rich galaxy cluster. Collectively they will provide a key database for
studies of galaxy formation and evolution. This survey will also help to
compare galaxies in different environments, both crowded and isolated,
as well as to compare relatively nearby galaxies to more distant ones
(at higher redshifts).
The Hubble Space Telescope is a project of international cooperation
between NASA and the European Space Agency (ESA) and is managed by
NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Md. The Space
Telescope Science Institute (STScI) conducts Hubble science operations.
The institute is operated for NASA by the Association of Universities
for Research in Astronomy, Inc., Washington, DC.
For more information on this story, contact:
Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu
Lars Lindberg Christensen
Hubble/ESA, Garching Germany
011-49-89-3200-6306
lars@eso.org