The Class 0 protostar, L483, has been observed in various molecular lines in the 1.2 mm band at a sub-arcsecond resolution with ALMA. An infalling-rotating envelope is traced by the CS line, while a very compact component with a broad velocity width is observed for the CS, SO, HNCO, NH2CHO, and HCOOCH3 lines. Although this source is regarded as the warm carbon-chain chemistry (WCCC) candidate source at a 1000 au scale, complex organic molecules characteristic of hot corinos such as NH2CHO and HCOOCH3 are detected in the vicinity of the protostar. Thus, both hot corino chemistry and WCCC are seen in L483. Although such a mixed chemical character source has been recognized as an intermediate source in previous single-dish observations, we here report the first spatially-resolved detection. A kinematic structure of the infalling-rotating envelope is roughly explained by a simple ballistic model with the protostellar mass of 0.1-0.2 M☉ and the radius of the centrifugal barrier (a half of the centrifugal radius) of 30-200 au, assuming the inclination angle of 80◦ (0◦ for a face-on). The broad line emission observed in the above molecules most likely comes from the disk component inside the centrifugal barrier. Thus, a drastic chemical change is seen around the centrifugal barrier.
|Publication status||Published - 2017 Mar 10|
- ISM: individual objects (L483)
- ISM: molecules
- Stars: formation
- Stars: pre-main
ASJC Scopus subject areas