# L483: Warm Carbon-Chain Chemistry Source Harboring Hot Corino Activity

## TL;DR

This study presents the first spatially-resolved observations of L483, revealing a unique combination of hot corino and warm carbon-chain chemistry, with a kinematic model explaining the infalling-rotating envelope and chemical variations near the centrifugal barrier.

## Contribution

It provides the first spatially-resolved detection of mixed chemical characteristics in L483, combining hot corino and WCCC features, and models the kinematic structure of its envelope.

## Key findings

- Detection of complex organic molecules near the protostar.
- Identification of a mixed chemical environment in L483.
- Kinematic modeling of the infalling-rotating envelope.

## Abstract

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, NH$_2$CHO, and HCOOCH$_3$ 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 NH$_2$CHO and HCOOCH$_3$ 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 $M_\odot$ and the radius of the centrifugal barrier (a half of the centrifugal radius) of 30--200 au, assuming the inclination angle of 80\degr\ (0\degr\ 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.