SF-04-0036

The potential of sulfur-bearing species to trace accretion processes in young protostars

Elizabeth Artur delaVillarmois, Viviana Guzman, Yao-Lun Yang, Nami Sakai

Sulfur-bearing molecules may have played an important role in the origins of life on Earth, however, the sulfur chemistry is poorly understood in the process of low-mass star and planet formation. Dense cores are depleted in S-bearing species, in comparison with ISM abundances, while deeply embedded protostars and cometary samples show different abundances of S-molecules. Furthermore, some of the simplest S-bearing species are hardly detected toward more evolved Class II disks and they seem to be more sensitive to the accretion of the forming protostar, providing information not only about the chemical content but also about the physical processes at play.
In this work, I will present observations of sulfur-bearing species (CS, SO, 34SO, and SO2) toward 50 Class 0/I sources that are part of the Perseus ALMA Chemistry Survey (PEACHES). We find that CS and SO are more sensitive to the evolutionary stage of the sources, while SO2 depends on the bolometric luminosity and, therefore, on the mass accretion rate. Sources with detections of S-bearing species but without detection of COMs seem to be related to infalling streamer and accretion shocks, ruling out the hot-corino origin. Finally, when compared to literature work, the Perseus star-forming region appears to be one of the regions with the highest depletion of sulfur.
This kind of large survey is essential to provide statistical results and broader conclusions regarding the poorly understood sulfur chemistry.