Sub-arcsecond Kinematic Structure of the Outflow in the Vicinity of the Protostar in L483

TL;DR

This study uses high-resolution ALMA observations to analyze the structure and kinematics of the outflow near a low-mass protostar, revealing its inclination, opening angle, and potential rotation, and comparing these with other sources.

Contribution

It provides detailed modeling of the outflow cavity wall in L483, constraining its inclination, opening angle, and rotation, and relates these to outflow evolution.

Findings

Outflow inclination is between 75 and 90 degrees.

The opening angle and gas velocity correlate with dynamical timescale.

Evidence suggests possible rotation of the outflow cavity wall.

Abstract

The bipolar outflow associated with the Class 0 low-mass protostellar source (IRAS 18148-0440) in L483 has been studied in the CCH and CS line emission at 245 and 262 GHz, respectively. Sub-arcsecond resolution observations of these lines have been conducted with ALMA. Structures and kinematics of the outflow cavity wall are investigated in the CS line, and are analyzed by using a parabolic model of an outflow. We constrain the inclination angle of the outflow to be from 75 degree to 90 degree, i.e. the outflow is blowing almost perpendicular to the line of sight. Comparing the outflow parameters derived from the model analysis with those of other sources, we confirm that the opening angle of the outflow and the gas velocity on its cavity wall correlate with the dynamical timescale of the outflows. Moreover, a hint of a rotating motion of the outflow cavity wall is found. Although the rotation motion is marginal, the specific angular momentum of the gas on the outflow cavity wall is evaluated to be comparable to or twice that of the infalling-rotating envelope of L483.