The Mice
| |
|
ZOOM
IN!
|
|
Located 300
million light-years away, colliding galaxies nicknamed The Mice
will eventually merge into a single giant galaxy.
Zoom
| Standard
| Wallpaper
|
|
|
These two galaxies are engaged in a celestial dance
of cat and mouse or, in this case, mouse and mouse.
Located 300 million light-years away in the constellation
Coma Berenices, the colliding galaxies have been nicknamed "The Mice" because
of the long tails of stars and gas emanating from each galaxy. Otherwise known
as NGC 4676, the pair will eventually merge into a single giant galaxy.
The image shows the most detail and the most stars
that have ever been seen in these galaxies. In the galaxy at left, the bright
blue patch is resolved into a vigorous cascade of clusters and associations
of young, hot blue stars, whose formation has been triggered by the tidal forces
of the gravitational interaction. Streams of material can also be seen flowing
between the two galaxies.
The clumps of young stars in the long, straight
tidal tail (upper right) are separated by fainter regions of material. These
dim regions suggest that the clumps of stars have formed from the gravitational
collapse of the gas and dust that once occupied those areas. Some of the clumps
have luminous masses comparable to dwarf galaxies that orbit in the halo of
our own Milky Way Galaxy.
Computer simulations by astronomers Josh Barnes
at the University of Hawaii and John Hibbard of the National Radio Astronomy
Observatory show that we are seeing two nearly identical spiral galaxies approximately
160 million years after their closest encounter.
The long, straight arm is actually curved, but
appears straight because we see it edge-on. The simulations also show that the
pair will eventually merge, forming a large, nearly spherical galaxy (known
as an elliptical galaxy). The stars, gas, and luminous clumps of stars in the
tidal tails will either fall back into the merged galaxies or orbit in the halo
of the newly formed elliptical galaxy.
The Mice presage what may happen to our own Milky
Way several billion years from now when it collides with our nearest large neighbor,
the Andromeda Galaxy (M31).
This picture is assembled from three sets of images
taken on April 7, 2002, in blue, orange, and near-infrared filters.
advertisement
