IRAS 18153-1651: an H II region with a possible wind bubble blown by a young main-sequence B star

TL;DR

This paper presents spectroscopic and numerical modeling evidence that IRAS 18153-1651 is a young H II region with a wind bubble created by a main-sequence B star, marking a rare observational case.

Contribution

It provides the first observational evidence of a wind bubble blown by a main-sequence B star, combining spectroscopy and radiation-hydrodynamics simulations.

Findings

The optical arc is the edge of a wind bubble from a B1 star.

Simulations match observed morphology and brightness.

IRAS 18153-1651 is a young, recently formed star cluster region.

Abstract

We report the results of spectroscopic observations and numerical modelling of the H II region IRAS 18153-1651. Our study was motivated by the discovery of an optical arc and two main-sequence stars of spectral type B1 and B3 near the centre of IRAS 18153-1651. We interpret the arc as the edge of the wind bubble (blown by the B1 star), whose brightness is enhanced by the interaction with a photoevaporation flow from a nearby molecular cloud. This interpretation implies that we deal with a unique case of a young massive star (the most massive member of a recently formed low-mass star cluster) caught just tens of thousands of years after its stellar wind has begun to blow a bubble into the surrounding dense medium. Our two-dimensional, radiation-hydrodynamics simulations of the wind bubble and the H II region around the B1 star provide a reasonable match to observations, both in terms of morphology and absolute brightness of the optical and mid-infrared emission, and verify the young age of IRAS 18153-1651. Taken together our results strongly suggest that we have revealed the first example of a wind bubble blown by a main-sequence B star.