A Survey of Sulfur-bearing Molecular Lines toward the Dense Cores in 11 Massive Protoclusters

Abstract Sulfur-bearing molecules are commonly detected in dense cores within star-forming regions, but the total sulfur budget is significantly lower when compared to the interstellar medium value. The properties of sulfur-bearing molecules are not well understood due to the absence of large sample studies with uniform observational configurations. To deepen our understanding of this subject, we conducted a study using Atacama Large Millimeter/submillimeter Array 870 μ m observations of 11 massive protoclusters. By checking the spectra of 248 dense cores in 11 massive protoclusters, a total of 10 sulfur-bearing species (CS, SO, H 2 CS, NS, SO 2 , 33 SO, 34 SO 2 , 33 SO 2 , SO 18 O, and OC 34 S) were identified. The parameters including systemic velocities, line widths, gas temperatures, column densities, and abundances were derived. Our results indicate that SO appears to be more easily detected in a wider range of physical environments than H 2 CS, despite these two species showing similarities in gas distributions and abundances. Molecules 34 SO 2 and H 2 CS are good tracers of the temperature of sulfur-bearing species, in which H 2 CS traces the outer warm envelope and 34 SO 2 is associated with high-temperature central regions. High-mass star-forming feedback (outflow and other nonthermal motions) significantly elevates the sulfur-bearing molecular abundances and detection rates specifically for SO 2 and SO. A positive correlation between the SO 2 abundance increasing factor ( F ) and temperatures suggests that SO 2 could serve as a sulfur reservoir on the grain mantles of dense cores and then can be desorbed from dust to gas phase as the temperature rises. This work shows the importance of a large and unbiased survey to understand the sulfur depletion in dense cores.