Images from Planck space observatory reveal star formation processes
By ANITuesday, April 27, 2010
WASHINGTON - Star formation takes place hidden behind veils of gas and dust, but ESA’s Planck space observatory with its microwave eyes - can peer beneath that shroud to provide new insights into star-forming process.
The latest images released by the Planck team bring to light two different star forming regions in the Milky Way, and in stunning detail, reveal the different physical processes at work.
The Orion region is a cradle of star formation, some 1,500 light-years away. It is famous for the Orion Nebula, which can be seen by the naked eye as a faint smudge.
The first image covers much of the constellation of Orion. The nebula is the bright spot to the lower center. The bright spot to the right of center is around the Horsehead Nebula, so called because at high magnifications a pillar of dust resembles a horse’s head.
The giant red arc of Barnard’s Loop is thought to be the blast wave from a star that blew up inside the region about two million years ago. The bubble it created is now about 300 light-years across.
In contrast to Orion, the Perseus region is a less vigorous star-forming area but, as Planck shows in the other image, there is still plenty going on.
The images both show three physical processes taking place in the dust and gas of the interstellar medium. Planck can show us each process separately.
At the lowest frequencies, Planck maps emission caused by high-speed electrons interacting with the Galaxy’s magnetic fields. An additional diffuse component comes from spinning dust particles emitting at these frequencies.
At intermediate wavelengths of a few millimeters, the emission is from gas heated by newly formed hot stars.
At still higher frequencies, Planck maps the meager heat given out by extremely cold dust. This can reveal the coldest cores in the clouds, which are approaching the final stages of collapse, before they are reborn as fully-fledged stars. The stars then disperse the surrounding clouds.
The delicate balance between cloud collapse and dispersion regulates the number of stars that the Galaxy makes. (ANI)
