| NASA Center: |
Hubble Space Telescope Center |
|---|
| Image # : |
PR99-41 |
|---|
| Date : |
11/04/1999
|
|---|
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Title
A Grazing Encounter Between Two Spiral Galaxies
Full Description
The larger and more massive galaxy is cataloged as NGC 2207 (on the
left in the Hubble Heritage image), and the smaller one on the right is
IC 2163. Strong tidal forces from NGC 2207 have distorted the shape of
IC 2163, flinging out stars and gas into long streamers stretching out a
hundred thousand light-years toward the right-hand edge of the image.
Computer simulations, carried out by a team led by Bruce and Debra
Elmegreen, demonstrate the leisurely timescale over which galactic
collisions occur. In addition to the Hubble images, measurements made
with the National Science Foundation's Very Large Array Radio Telescope
in New Mexico reveal the motions of the galaxies and aid the
reconstruction of the collision.
The calculations indicate that IC 2163 is swinging past NGC 2207 in a
counterclockwise direction, having made its closest approach 40 million years
ago.
However, IC 2163 does not have sufficient energy to escape from the
gravitational pull of NGC 2207, and is destined to be pulled back and swing past
the larger galaxy again in the future.
The high resolution of the Hubble telescope image reveals dust lanes in the
spiral arms of NGC 2207, clearly silhouetted against IC 2163, which is in the
background. Hubble also reveals a series of parallel dust filaments extending
like fine brush strokes along the tidally stretched material on the right-hand
side. The large concentrations of gas and dust in both galaxies may well erupt
into regions of active star formation in the near future.
Trapped in their mutual orbit around each other, these two galaxies will
continue to distort and disrupt each other. Eventually, billions of years from
now, they will merge into a single, more massive galaxy. It is believed that
many present-day galaxies, including the Milky Way, were assembled from a
similar process of coalescence of smaller galaxies occurring over billions of
years.
This image was created from 3 separate pointings of Hubble. The Wide Field
Planetary Camera 2 data sets were obtained by Debra Meloy Elmegreen (Vassar
College), Bruce G. Elmegreen (IBM Research Division), Michele Kaufman (Ohio
State U.), Elias Brinks (Universidad de Guanajuato, Mexico), Curt Struck (Iowa
State University), Magnus Thomasson (Onsala Space Obs., Sweden), Maria Sundin
(Goteborg University, Sweden), and Mario Klaric (Columbia, South Carolina).
Keywords
Hubble Space Telescope HST NGC 2207 Milky Way Wide Field Planetary Camera WFPC
Subject Category
Deep Space Studies, Hubble,
Reference Numbers
- Center:
HSTI
- Center Number:
PR99-41
- GRIN DataBase Number:
GPN-2000-000897
Source Information
- Creator/Photographer: NASA, The Hubble Heritage Team, STScI, AURA
- Original Source: DIGITAL
| Resolution | Format | Width
(Pixels) | Height
(Pixels) | Size
(KBytes) |
Thumbnail |
.jpg |
95 |
80 |
18 |
Small |
.jpg |
1116 |
570 |
708 |
Medium |
.jpg |
2616 |
1337 |
2,886 |
Large |
.jpg |
2907 |
1486 |
3,423 |
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Updated October 31, 2002
• History Questions: NASA History Office
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