Detection of monothioformic acid towards the solar-type protostar IRAS 16293–2422

In the interstellar medium (ISM), complex organic molecules that contain thiol group ($-$SH) play an important role in polymerization of amino acids. We look for SH-bearing chemically rich solar-type protostar IRAS 16293-2422. After extensive spectral analysis using local thermodynamic equilibrium (LTE) model, we have detected rotational emission lines trans-isomer monothioformic acid (t-HC(O)SH) towards 16293 B Atacama Large Millimeter/Submillimeter Array (ALMA). did not observe any evidence cis-isomer (c-HC(O)SH) B. The column density t-HC(O)SH was (1.02$\pm$0.6)$\times$10$^{15}$ cm$^{-2}$ with excitation temperature 125$\pm$15 K. fractional abundance respect to H$_{2}$ is 8.50$\times$10$^{-11}$. ratio t-HC(O)SH/CH$_{3}$SH 0.185. compare our estimated galactic center quiescent cloud G+0.693-0.027 and hot molecular core G31.41+0.31. comparison, found several times magnitude lower than also discuss possible formation mechanism ISM.