Poster Version
Click on the image for high resolution image
NASA's Spitzer Space Telescope has captured a new, infrared view of the
choppy star-making cloud called M17, or the Swan nebula.
The cloud, located about 6,000 light-years away in the constellation
Sagittarius, is dominated by a central group of massive stars—the
most massive stars in the region (see yellow circle in poster version
above). These central stars give off intense flows of expanding gas, which
rush like rivers against dense piles of material, carving out the deep
pocket at center of the picture. Winds from the region's other massive
stars push back against these oncoming rivers, creating bow shocks like
those that pile up in front of speeding boats.
Three of these bow shocks are labeled in the magnified inset. They are
composed of compressed gas in addition to dust that glows at infrared
wavelengths Spitzer can see. The smiley-shaped bow shocks curve away from
the stellar winds of the central massive stars.
This picture was taken with Spitzer's infrared array camera. It is a
four-color composite, in which light with a wavelength of 3.6 microns is
blue; 4.5-micron light is green; 5.8-micron light is orange; and 8-micron
light is red. Dust is red, hot gas is green and white is where gas and
dust intermingle. Foreground and background stars appear scattered through
the image.
