CHED 1624 |
| At present, over 130 different chemical compounds have been discovered in interstellar space. The identification of these molecules results from a joint effort of laboratory spectroscopists and radio astronomers. The laboratory work concerns the measurement of rotational transitions of molecules to accuracies of one part in 107-108 using several techniques, including direct absorption, Fourier transform microwave, and velocity modulation methods. Very often, exotic syntheses of molecules involving discharges, ovens, and pulsed nozzles are required. Radio astronomers can then take the measured “rest frequencies” to a telescope and see if the spectrum of a certain species is present in a given interstellar source, such as a molecular cloud or the ejecta of an aging star. This task is often quite complicated because interstellar sources can be very rich in spectral lines. The complete process by which an identification is finally achieved, both the laboratory and astronomical aspects, will be discussed. |
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Chemical Evolution, Chemical Change Across Space and Time
1:30 PM-4:45 PM, Tuesday, March 27, 2007 McCormick Place North -- Room N227A, Level 2, Oral
Division of Chemical Education |