RCW 108 is a region where stars are actively forming within the Milky Way
galaxy about 4,000 light years from Earth. This is a complicated region
that contains young star clusters, including one that is deeply embedded
in a cloud of molecular hydrogen. By using data from different telescopes,
astronomers determined that star birth in this region is being triggered
by the effect of nearby, massive young stars.
This image is a composite of X-ray data from NASA's Chandra X-ray
Observatory (blue) and infrared emission detected by NASA's Spitzer Space
Telescope (red and orange). More than 400 X-ray sources were identified in
Chandra's observations of RCW 108. About 90 percent of these X-ray sources
are thought to be part of the cluster and not stars that lie in the
field-of-view either behind or in front of it. Many of the stars in RCW
108 are experiencing the violent flaring seen in other young star-forming
regions such as the Orion nebula. Gas and dust blocks much of the X-rays
from the juvenile stars located in the center of the image, explaining the
relative dearth of Chandra sources in this part of the image.
The Spitzer data show the location of the embedded star cluster, which
appears as the bright knot of red and orange just to the left of the
center of the image. Some stars from a larger cluster, known as NGC 6193,
are also visible on the left side of the image. Astronomers think that the
dense clouds within RCW 108 are in the process of being destroyed by
intense radiation emanating from hot and massive stars in NGC 6193.
Taken together, the Chandra and Spitzer data indicate that there are more
massive star candidates than expected in several areas of this image. This
suggests that pockets within RCW 108 underwent localized episodes of star
formation. Scientists predict that this type of star formation is
triggered by the effects of radiation from bright, massive stars such as
those in NGC 6193. This radiation may cause the interior of gas clouds in
RCW 108 to be compressed, leading to gravitational collapse and the
formation of new stars.
