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Дата изменения: Tue Apr 10 19:35:38 2001
Дата индексирования: Sat Dec 22 09:10:08 2007
Кодировка:

Поисковые слова: galaxy pair
Dust in Spiral <b style="color:black;background-color:#ffff66">Galaxies</b>
                                       GALACTIC SILHOUETTES 

This new image from NASA's Hubble Space Telescope and its Wide Field Planetary Camera 2 (WFPC2) shows the unique galaxy pair called NGC 3314. Through an
extraordinary chance alignment, a face-on spiral galaxy lies precisely in front of another larger spiral. This line-up provides us with the rare chance to visualize dark
material within the front galaxy, seen only because it is silhouetted against the object behind it. 

Dust lying in the spiral arms of the foreground galaxy stands out where it absorbs light from the more distant galaxy. This silhouetting shows us where the interstellar
dust clouds are located, and how much light they absorb. The outer spiral arms of the front galaxy appear to change from bright to dark, as they are projected first
against deep space, and then against the bright background of the other galaxy. 

NGC 3314 lies about 140 million light-years from Earth, in the direction of the southern hemisphere constellation Hydra. The bright blue stars forming a pinwheel
shape near the center of the front galaxy have formed recently from interstellar gas and dust. 

In many galaxies, interstellar dust lies only in the same regions as recently formed blue stars. However, in the foreground galaxy, NGC 3314a, there are numerous
additional dark dust lanes that are not associated with any bright young stars. 

A small, red patch near the center of the image is the bright nucleus of the background galaxy, NGC 3314b. It is reddened for the same reason the setting sun looks
red. When light passes through a volume containing small particles (molecules in the Earth's atmosphere or interstellar dust particles in galaxies), its color becomes
redder. 

The Hubble Heritage color image of NGC 3314 was constructed from archival images taken with WFPC2 in April 1999 by Drs. William Keel and Ray White III
(University of Alabama) in blue and infrared light, combined with new images obtained by the Heritage team in March 2000 using blue, green and red filters. 

Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) 

Acknowledgments: William Keel (U. Alabama)