Intermittent maser flare around the high mass young stellar object G353.273+0.641 II: Detection of a radio and molecular jet

TL;DR

This paper reports the first detection of a radio and molecular jet associated with the high-mass young stellar object G353.273+0.641, revealing a bipolar jet structure and a maser-scale molecular jet likely obscured by a disc.

Contribution

It presents the first combined detection of radio continuum, H$_{2}$O masers, and SiO molecular emission in G353.273+0.641, proposing a new disc-masking scenario for blue-shift dominance.

Findings

Detection of a 3000 au radio jet aligned NW-SE.

Identification of a maser-scale molecular jet enclosed by the radio jet.

Spectral similarity indicating a bipolar jet structure.

Abstract

We report the first detection of a radio-continuum and molecular jet associated with a dominant blue-shifted maser source, G353.273+0.641. A radio jet is extended 3000 au along NW-SE direction. H$_{2}$O masers are found to be clustered in the root of a bipolar radio jet. A molecular jet is detected by thermal SiO ($\upsilon$ = 0, $J$ = 2-1) emission. The SiO spectrum is extremely wide (-120 -- +87 km s$^{-1}$) and significantly blue-shift dominated, similar to the maser emission. The observed geometry and remarkable spectral similarity between H$_{2}$O maser and SiO strongly suggests the existence of a maser-scale ($\sim$ 340 au) molecular jet that is enclosed by the extended radio jet. We propose a "disc-masking" scenario as the origin of the strong blue-shift dominance, where an optically thick disc obscures a red-shifted lobe of a compact jet.