Comparison of the observed spectra (gray) and the synthesized acetone spectra (green) in LTE at 1.3 and 3 mm toward Ace-1. The observed spectra are plotted at their original synthesized beam sizes of (101 GHz) and (223 GHz). The acetone synthesized spectra near 101 GHz (upper panel) were produced by assuming a (CH₃)₂CO column density of 3 × 10¹⁶ cm^-2 and a temperature of 160 K, and the acetone synthesized spectra near 223 GHz (lower panel) were produced assuming a (CH₃)₂CO column density of 4 × 10¹⁶ cm^-2 with the same temperature. Line widths of acetone synthesized spectra 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. Synthesized ¹³C-substituted C₂H₅CN spectra are shown in red, assuming a column density of 2 × 10¹⁴ cm^-2 and a temperature of 160 K. Their contributions to the acetone lines blending are minor. In addition, the methyl formate synthesized spectra (blue) are also shown for comparison.