2024RAA....24f5008M

The observation of oxygen (O)- and nitrogen (N)-bearing molecules gives an idea about the complex prebiotic chemistry in the interstellar medium. Recent millimeter and submillimeter wavelength observations have shown the presence of complex O- and N-bearing molecules in the star formation regions. So, the investigation of those molecules is crucial to understanding the chemical complexity in the star-forming regions. In this article, we present the identification of the rotational emission lines of N-bearing molecules ethyl cyanide (${{\rm{C}}}_{2}{{\rm{H}}}_{5}\mathrm{CN}$) and cyanoacetylene (HC₃N), and O-bearing molecule methyl formate (CH₃OCHO) toward high-mass protostar IRAS 18089-1732 using the Atacama Compact Array. We also detected the emission lines of both the N- and O-bearing molecule formamide (NH₂CHO) in the envelope of IRAS 18089-1732. We have detected the v = 0 and 1 state rotational emission lines of CH₃OCHO. We also detected the two vibrationally excited states of HC₃N (v7 = 1 and v7 = 2). The estimated fractional abundances of ${{\rm{C}}}_{2}{{\rm{H}}}_{5}\mathrm{CN}$, HC₃N (v7 = 1), HC₃N (v7 = 2), and NH₂CHO toward IRAS 18089-1732 are (1.40 ± 0.5) × 10^–10, (7.5 ± 0.7) × 10^–11, (3.1 ± 0.4) × 10^–11, and (6.25 ± 0.82) × 10^–11 respectively. Similarly, the estimated fractional abundances of CH₃OCHO (v = 0) and CH₃OCHO (v = 1) are (1.90 ± 0.9) × 10^–9 and (8.90 ± 0.8) × 10^–10, respectively. We also created the integrated emission maps of the detected molecules, and the observed molecules may have originated from the extended envelope of the protostar. We show that ${{\rm{C}}}_{2}{{\rm{H}}}_{5}\mathrm{CN}$ and HC₃N are most probably formed via the subsequential hydrogenation of the ${\mathrm{CH}}_{2}\mathrm{CHCN}$ and the reaction between C₂H₂ and CN on the grain surface of IRAS 18089-1732. We found that NH₂CHO is probably produced due to the reaction between NH₂ and H₂CO in the gas phase. Similarly, CH₃OCHO is possibly created via the reaction between radical CH₃O and radical HCO on the grain surface of IRAS 18089-1732.