2019ApJ...880..130M

We have observed 29 transitions corresponding to 12 distinct species and 7 additional isotopologues toward the deeply embedded Class 0 young stellar object Ser-emb 1 with the Atacama Large Millimeter/submillimeter Array at ∼1 mm. The detected species include CH₃OH and two complex organic molecules, CH₃OCH₃ and CH₃OCHO. The emission of CH₃OH and the two COMs is compact, and the CH₃OH rotational temperature is 261 ± 46 K, implying that Ser-emb 1 hosts a hot corino. The derived CH₃OH, CH₃OCH₃, and CH₃OCHO column densities are at least (1.2 ± 0.4) x 10¹⁷ cm^–2, (9.2 ± 3.8) x 10¹⁶ cm^–2, and (9.1 ± 3.6) x 10¹⁶ cm^–2, respectively, comparable to the values found for other Class 0 hot corinos. In addition, we observe evidence of rotation at compact scales: two of the more strongly detected lines, corresponding to C¹⁸O and H₂CO present spatially resolved redshifted and blueshifted compact emission orthogonal to the direction of a jet and outflow traced by CO, SiO, and several other molecules. The spatial coincidence of the hot corino emission and a possible disk in a compact region around the central protostar suggests that these structures may be physically and/or chemically related.