Tracing the Bipolar Outflow from Orion Source I

TL;DR

This study uses high-resolution imaging to map the bipolar outflow from Orion Source I, revealing its structure, direction changes over time, and its connection to the larger outflow in Orion-KL.

Contribution

It provides detailed imaging of the bipolar outflow from Orion Source I at 87 GHz, confirming its alignment and dynamic evolution, which advances understanding of outflow mechanisms in star-forming regions.

Findings

Radio source I drives a bipolar outflow along NE--SW axis.

High velocity outflow extends along NW--SE axis, indicating directional change.

Outflow structures are consistent with previous models and observations.

Abstract

Using CARMA, we imaged the 87 GHz SiO v=0 J=2-1 line toward Orion-KL with 0.45 arcsec angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE--SW axis, in agreement with the model of Greenhill et al. (2004). The extended high velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High velocity gas extends farthest along a NW--SE axis, suggesting that the outflow direction changes on time scales of a few hundred years.