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Steve Roy
Media Relations Dept.
Marshall Space Flight Center, Huntsville, AL
steve.roy{at}msfc.nasa.gov
(256) 544-0034

For release: 02-19-03

Photo release no.: 03-030

Chandra and Hubble compose stunning picture of spiral galaxy
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Composite image of the spiral galaxy NGC 3079: Superwind
sculpts filamentary features

[http://www1.msfc.nasa.gov/NEWSROOM/news/photos
             /2003/photos03-030.html]

A Chandra X-ray Observatory image, in blue, has been combined with 
Hubble's optical image, in red and green, to compose this stunning and 
revealing picture of the spiral galaxy NGC 3079. Towering filaments 
consisting of warm (about ten thousand degrees Celsius) and hot (about 
ten million degrees Celsius) gas blend to create the bright 
horseshoe-shaped feature near the center.

The correlation of the warm and hot filaments suggests that they were 
both formed as a superwind of gas -- rushing out from the central 
regions of the galaxy -- carved a cavity in the cool gas of the 
galactic disk.  The superwind stripped fragments of gas off the walls
of the cavity, stretched them into long filaments, and heated them. 
The full extent of the superwind shows up as a fainter conical cloud 
of X-ray emission surrounding the filaments.

A superwind, such as the one in NGC 3079, originates in the center of 
the galaxy either from activity generated by a central supermassive 
black hole or by a burst of supernova activity. Superwinds are thought 
to play a key role in the evolution of galaxies by regulating the
formation of new stars, and by dispersing heavy elements to the outer 
parts of the galaxy and beyond. These latest Chandra data indicate 
that astronomers may be seriously underestimating the mass lost in 
superwinds and, therefore, their influence within and around the host 
galaxy.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the 
Chandra program for NASA. (NASA/CXC /U.  North Carolina/G. Cecil)

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