Organic Complexity in Protostellar Disk Candidates

We present ALMA observations of organic molecules toward five low-mass Class 0/I protostellar disk candidates in the Serpens cluster. Three sources (Ser-emb 1, Ser-emb 8, and Ser-emb 17) present emission of CH₃OH as well as CH₃OCH₃, CH₃OCHO, and CH₂CO, while NH₂CHO is detected in just Ser-emb 8 and Ser-emb 17. Detecting hot corino-type chemistry in three of five sources represents a high occurrence rate given the relative sparsity of these sources in the literature, and this suggests a possible link between protostellar disk formation and hot corino formation. For sources with CH₃OH detections, we derive column densities of 10¹⁷-10¹⁸ cm^-2 and rotational temperatures of ∼200-250 K. The CH₃OH-normalized column density ratios of large, oxygen-bearing COMs in the Serpens sources and other hot corinos span 2 orders of magnitude, demonstrating a high degree of chemical diversity at the hot corino stage. Resolved observations of a larger sample of objects are needed to understand the origins of chemical diversity in hot corinos, and the relationship between different protostellar structural elements on disk-forming scales.