2016ApJ...819..140G

Large interstellar organic molecules are potential precursors of prebiotic molecules. Their formation pathways and chemical relationships with one another and simpler molecules are therefore of great interest. In this paper we address the relationships between two classes of large organic molecules, carbon chains and saturated complex organic molecules at the early stages of star formation through observations of C₄ H and CH₃OH. We surveyed these molecules with the IRAM 30 m telescope toward 16 deeply embedded low-mass protostars selected from the Spitzer c2d ice survey. We find that CH₃OH and C₄H are positively correlated, indicating that these two classes of molecules can coexist during the embedded protostellar stage. The C₄H/CH₃OH gas abundance ratio tentatively correlates with the CH₄/CH₃OH ice abundance ratio in the same lines of sight. This relationship supports a scenario where carbon chain formation in protostellar envelopes begins with CH₄ice desorption. Interstellar Medium