Disruption of the Orion Molecular Core 1 by the stellar wind of the massive star ${\theta}^1$ Ori C

TL;DR

This study uses [C II] line observations to show that the stellar wind from ${ heta}^1$ Ori C has significantly disrupted the Orion Molecular Core 1 by creating an expanding bubble, surpassing other feedback mechanisms.

Contribution

It provides the first direct observational evidence that stellar wind mechanical energy dominates molecular cloud disruption in Orion core 1.

Findings

Stellar wind created a 4 parsec bubble with a 2,600 solar mass shell.

The shell expands at 13 km/s, indicating efficient energy transfer.

Stellar wind disruption exceeds photo-ionization and supernova effects.

Abstract

Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new stars). Stellar winds, supernova explosions and ionization by ultraviolet photons control the lifetimes of molecular clouds. Theoretical studies predict that momentum injection by radiation should dominate that by stellar winds, but this has been difficult to assess observationally. Velocity-resolved large-scale images in the fine-structure line of ionized carbon ([C II]) provide an observational diagnostic for the radiative energy input and the dynamics of the interstellar medium around massive stars. Here we report observations of a one-square-degree region (about 7 parsecs in diameter) of Orion molecular core -- the region nearest to Earth that exhibits massive-star formation -- at a resolution of 16 arcseconds (0.03 parsecs) in the [C II] line at 1.9 terahertz (158 micrometres). The results reveal that the stellar wind originating from the massive star ${\theta}^{1}$ Orionis C has swept up the surrounding material to create a bubble roughly four parsecs in diameter with a 2,600-solar-mass shell, which is expanding at 13 kilometres per second. This finding demonstrates that the mechanical energy from the stellar wind is converted very efficiently into kinetic energy of the shell and causes more disruption of the Orion molecular core 1 than do photo-ionization and evaporation or future supernova explosions.