Discovery of a New Molecular Bubble-Outflow Structure in the Taurus B18 Cloud

TL;DR

This paper reports the discovery of a new molecular bubble with an outflow in the Taurus B18 cloud, providing insights into stellar feedback mechanisms in low- and intermediate-mass star formation regions.

Contribution

It identifies a novel bubble-outflow structure associated with T Tauri stars, expanding understanding of stellar feedback effects on molecular clouds.

Findings

The bubble has a kinetic energy of 5.8 x 10^43 erg.

The bubble formed approximately 70,000 years ago.

Proper motions suggest T Tauri stars may have created the structure.

Abstract

Star formation can produce bubbles and outflows, as a result of stellar feedback. Outflows and bubbles inject momentum and energy into the surrounding interstellar medium, and so are related to the overall energy balance of the molecular cloud. Molecular bubbles can be resolved by higher-resolution radio telescopes to quantify the effect of star formation on molecular clouds. We report here the identification of a new molecular bubble with an outflow, and an Herbig Haro object, HH319, located at the bubble center. Multi-wavelength data have been utilized to study its spatial structure, energy injection, and dynamical timescale. This bubble has a kinetic energy of $\rm 5.8 \times 10^{43}$ erg within the smallest radius of a bubble in Taurus, 0.077 pc. The bubble formed $\sim$70,000 years ago. According to the proper motion velocities of protostars from $Gaia$ EDR3, the T Tauri binary stars (FY Tau and FZ Tau) at the southwest edge of the bubble may have produced the outflow-bubble structure. This is an unusual new structure found in low- and intermediate-mass star formation regions. Only a bubble in Orion A, driven by V380 Ori, has a similar structure. The bubble-outflow structure provides additional observational evidence for the theory of stellar wind from T Tauri stars. It enhances our understanding of how stellar feedback acts on molecular clouds.