Comparison of the observed spectra (gray) and the synthesized acetone spectra (green) in LTE near 229 GHz toward Ace-1. The observed spectra are plotted at the original synthesized beam size of . The acetone synthesized spectra were produced assuming a (CH₃)₂CO column density of 1.7 × 10¹⁶ cm^-2 and a temperature of 160 K, and the line widths of acetone were fixed at 3.5 km s^-1. As in Table 2, only the transitions with E_up < 300 K are indicated with their frequencies (in MHz), and the others are all blended. In addition, the methyl formate synthesized spectra (blue) are also shown for comparison.