The Radio Jet Associated with the Multiple V380 Ori System

TL;DR

This paper reports the detection of a thermal radio jet associated with the Herbig Be star in the V380 Ori system, likely driving the large-scale Herbig-Haro outflow HH 222, providing insights into the jet's origin and evolution.

Contribution

It presents the first detection of a thermal radio jet linked to V380 Ori, clarifying the source of the HH 222 outflow and its evolutionary status.

Findings

Detected elongated radio source aligned with HH 222 outflow

Radio luminosity is smaller than expected from the radio-bolometric correlation

Supports V380 Ori as the origin of the large-scale outflow

Abstract

The giant Herbig-Haro object 222 extends over $\sim$6$'$ in the plane of the sky, with a bow shock morphology. The identification of its exciting source has remained uncertain over the years. A non-thermal radio source located at the core of the shock structure was proposed to be the exciting source. However, Very Large Array studies showed that the radio source has a clear morphology of radio galaxy and a lack of flux variations or proper motions, favoring an extragalactic origin. Recently, an optical-IR study proposed that this giant HH object is driven by the multiple stellar system V380 Ori, located about 23$'$ to the SE of HH 222. The exciting sources of HH systems are usually detected as weak free-free emitters at centimeter wavelengths. Here we report the detection of an elongated radio source associated with the Herbig Be star or with its close infrared companion in the multiple V380 Ori system. This radio source has the characteristics of a thermal radio jet and is aligned with the direction of the giant outflow defined by HH~222 and its suggested counterpart to the SE, HH~1041. We propose that this radio jet traces the origin of the large scale HH outflow. Assuming that the jet arises from the Herbig Be star, the radio luminosity is a few times smaller than the value expected from the radio-bolometric correlation for radio jets, confirming that this is a more evolved object than those used to establish the correlation.