The spatial scale of glycolaldehyde in the galactic center

We previously reported the spectral detection of the first interstellar sug ar, which is known as glycolaldehyde (CH2OHCHO), by observing six separate millimeter-wave rotational transitions with the NRAO 12 m telescope while p ointed toward the Sagittarius B2 North hot core source known as the Large M olecule Heimat (LMH) source. In the present BIMA array work, we have spatia lly mapped Sgr B2 using the 8(08)-7(17) transition of glycolaldehyde at 82. 4 GHz. We find that glycolaldehyde has a spatial scale of greater than or e qual to 60" unlike its isomers methyl formate and acetic acid, which are co ncentrated in the LMH source that has a spatial scale of less than or equal to5". We estimate that the relative abundance ratios of (acetic acid): (gl ycolaldehyde) :(methyl formate) are similar to1 :0.5:26 within the LMH sour ce. It is likely that the conditions of the LMH source favor the chemically reactive nature of glycolaldehyde over its isomers and other large molecul es such as dimethyl ether. The ensuing chemistry leads to glycolaldehyde de struction in the LMH source and glycolaldehyde survival outside of the LMH source in extended cloud extremities. This scenario is supported by compari son of line widths. which shows that glycol aldehyde possesses a factor of 2-3 greater line width than those of other complex molecules that are confi ned largely to the LMH source.