The millimeter- and submillimeter-wave spectrum of glycolaldehyde (CH2OHCHO)

The simplest monosaccharide, glycolaldehyde (CH2OHCHO), has recently been d etected toward the Galactic center in the source Sgr B2(N) at five frequenc ies from 71-104 GHz. None of the individual lines used in the detection had been measured previously in the laboratory; rather, their frequencies were predicted based on lower frequency measurements. We have now recorded and analyzed many new rotational transitions of glycolaldehyde through 354 GHz using two spectrometers. Lines through 48 GHz in frequency were measured wi th a spectrometer that uses Stark modulation, while the higher frequency tr ansitions were measured with a FASSST (Fast Scan Submillimeter Spectroscopi c Technique) apparatus. Analysis of the data has allowed us to confirm the interstellar identifications and to predict the frequencies of many additio nal lines not measured in the laboratory.