Probing the Inner 200 AU of Low-Mass Protostars with the Submillimeter Array: Dust and Organic Molecules in NGC 1333 IRAS 2A

摘要: The Submillimeter Array has opened a new window to study the innermost warm and dense regions of envelopes disks around deeply embedded protostars. This paper presents high angular resolution (<2'') submillimeter observations Class 0 young stellar object NGC 1333 IRAS 2A. Dust continuum emission lines complex organic molecules such as CH3OCH3 CH3OCHO, high-excitation CH3OH transitions, deuterated methanol, CH3OD, well CO, HCN, H13CN, SO, SO2, are detected on 200 AU scales. interpreted using detailed radiative transfer models physical chemical structure, consistent with both single-dish interferometer data. is explained by an extended envelope compact but resolved component, presumably circumstellar disk diameter 200-300 mass ~a few times 0.01-0.1 M?. If it related rotation envelope, then size this suggests centrifugal barrier AU, which implies that temperature in does not increase above 100 K. Its large also buildup proceeds rapidly throughout early protostellar stages. smaller (<100 AU) found other protostars may be result tidal truncation. high-resolution SO can simple constant abundance, ~10-9, constrained through observations, whereas those H13CN species require abundances, increased 1-2 orders magnitude, or additional source at small molecular could originate hot-core region inner more likely reservoir disk.