Carbon Monoxide All-Sky Survey
Carbon Monoxide All-Sky Survey
| Group Name | mwCO |
| Reference | Composite CO Survey of the Milky Way
(Dame et al. 1987) |
| Prepared by | Brian Abbott (AMNH/Hayden) |
| Labels | No |
| Files | mw-CO.speck |
| Dependencies | 03-115GHz-512.sgi |
| Wavelength | 2.6 mm |
| Frequency | 115 GHz |
Carbon monoxide (CO) is about 10,000 times less abundant than molecular hydrogen, yet we see traces of CO via its radio signature line at 2.6 millimeters (115 GHz). Using radio telescopes, astronomers observe this portion of the radio spectrum where the atmosphere is semitransparent. The observations used to compose this image were made with the Columbia/GISS 1.2-meter telescope in New York City as well as telescopes at Cerro Tololo in Chile.
CO is used to trace molecular hydrogen (H2). Normally, CO molecules would be broken apart by the ultraviolet radiation from stars. However, the CO molecules remain shielded from the harmful UV rays deep inside dense, dusty molecular clouds of hydrogen.
The Orion Nebula is the best example of a nearby giant molecular cloud. The nebula sits on the edge of a much larger cloud that is invisible to us in optical light. However, the cooler atomic hydrogen and CO radiate in this region of the EM spectrum. We observe CO mainly in the Galactic plane, where most of the gas and dust are concentrated in our Galaxy and star formation occurs. If we see CO, we can expect to see new stars.
CO intensity is represented by colors mapped to the intensity of the CO spectral line. The violet and blue regions are less intense and the red and white regions are of higher intensity. The survey covers the entire range in Galactic longitude but only a narrow band centered on the Galactic equator. Because CO is confined to the plane of the Galaxy, this is a reasonable range in Galactic latitude.
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott