ALMASOP. A Rotating Feature Rich in Complex Organic Molecules in a Protostellar Core

TL;DR

This paper reports the discovery of a rotating feature rich in complex organic molecules within a protostellar core, suggesting localized chemical complexity potentially linked to prebiotic chemistry in early stellar systems.

Contribution

It identifies a COM-enriched rotating feature near a protostellar disk and proposes accretion shocks as a possible origin, advancing understanding of chemical processes in star formation.

Findings

Detection of COM-rich feature near the Keplerian disk boundary

Distinct chemical behaviors of molecules indicating varied physical conditions

Evidence supporting accretion shocks as a source of COM enrichment

Abstract

Interstellar complex organic molecules (COMs) in solar-like young stellar objects (YSOs), particularly within protostellar disks, are of significant interest due to their potential connection to prebiotic chemistry in emerging planetary systems. We report the discovery of a rotating feature enriched in COMs, including CH3OH, CH3CHO, and NH2CHO, in the protostellar core G192.12-11.10. By constructing a YSO model, we find that the COM-rich feature is likely located within or near the boundary of the Keplerian disk. The image synthesis results suggest that additional heating mechanisms leading to a warm ring or a warm inner disk are required to reproduce the observed emission. We discuss possible origins of the COM-rich feature, particularly accretion shocks as a plausible cause for a warm ring. Additionally, molecules such as C18O, H2CO, DCS, H2S, and OCS exhibit distinct behavior compared to CH3OH, indicating a range of physical and chemical conditions within the region. The observed kinematics of H2S and OCS suggest that OCS resides in regions closer to the central protostar than H2S, consistent with previous experimental studies.