Unlocking the sulphur chemistry in intermediate-mass protostars of Cygnus X

Context. The chemistry of sulphur-bearing species in the interstellar medium remains poorly understood, but might play a key role chemical evolution star-forming regions. Aims. Coupling laboratory experiments to observations different parts regions, we aim understand behavior sulphur cold and warm regions protostars, ultimately hope connect them. Methods. We performed which tested reactivity hydrogen sulfide (H 2 S) on substrate with and/or carbon monoxide (CO) under physical conditions that allowed us determine products from reactions using quadrupole mass spectrometer. were complemented by observations. observed two luminous binary sources Cygnus-X complex, Cygnus X-N30 N12, covering frequency range 329–361 GHz at spatial resolution 1′′5 SubMillimeter Array (SMA). This study was 3 mm line survey X-N12 specific windows ranges 72.0–79.8 34′′0–30′′0 84.2–115.5 29′′0–21′′0, IRAM-30 m single-dish telescope. Column densities excitation temperatures derived local thermodynamic equilibrium approximation. Results. find OCS is direct product H S reacting CO ( T < 100 K) experiments. therefore found be an important solid-state S-reservoir. identify several S-species envelope Cyg X-N12, principally organo-sulphurs CS, OCS, CCS, C S, CH SH, HSCN). For hot cores N30, only CS detected. difference S-diversity between core likely due sensitivity toward N12. Moreover, based analysis driven processes rather than low Furthermore, column density ratio N / SO also indicator > 1), 1) chemistries within same source. molecular abundances inferred for are similar protostars N30 N12 depends protostellar component targeted (i.e., or core) source itself. However, distribution emission shows differences compared N12: all peaks continuum sources, whereas spatially distributed variations families (N, O, families) N30. this identified offset peaks. molecules good tracers provide insight into type object observed.