Bow shocks in water fountain jets

TL;DR

This paper studies water fountain jets with bipolar bow shocks, revealing episodic jet outbursts likely caused by episodic accretion in binary systems, through VLBI maser astrometry.

Contribution

It presents the first detailed VLBI maser analysis of two water fountains, uncovering episodic jet activity and its possible link to binary accretion processes.

Findings

Jets are formed in short-lived, episodic outbursts.

Maser structures and velocities indicate episodic jet activity.

Evidence suggests binary system accretion drives jet episodicity.

Abstract

We briefly introduce the VLBI maser astrometric analysis of IRAS 18043-2116 and IRAS 18113-2503, two remarkable and unusual water fountains with spectacular bipolar bow shocks in their high-speed collimated jet-driven outflows. The 22 GHz H2O maser structures and velocities clearly show that the jets are formed in very short-lived, episodic outbursts, which may indicate episodic accretion in an underlying binary system.