GREAT infrared spectrum of M17
GREAT infrared spectrum of M17
GREAT collected its first terahertz photons from the M17SW star forming cloud on 6 April 2011. Superposed on a near-infrared false-colour image obtained with the Spitzer Space Telescope (NASA/JPL-Caltech/M. Povich, Univ. Wisc.), you will see selected spectra of ionized carbon ([CII], white line) and warm carbon monoxide (CO, green line). The high spectral resolution of GREAT is necessary to study the velocity structure across the cloud, as unveiled by the different line profiles.
The field studied in the sky is overlaid on the infrared image, and the velocity integrated distribution of [CII] and CO is displayed in the inserts at the bottom. The data obtained with GREAT shows the warm interface of the M17 molecular cloud exposed to the ionizing radiation of nearby massive stars.
