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arXiv · 1711.09927

A clustered origin for isolated massive stars

William E. Lucas·Matus Rybak·Ian A. Bonnell·Mark Gieles
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Abstract

High-mass stars are commonly found in stellar clusters promoting the idea that their formation occurs due to the physical processes linked with a young stellar cluster. It has recently been reported that isolated high-mass stars are present in the Large Magellanic Cloud. Due to their low velocities it has been argued that these are high-mass stars which formed without a surrounding stellar cluster. In this paper we present an alternative explanation for the origin of these stars in which they formed in a cluster environment but are subsequently dispersed into the field as their natal cluster is tidally disrupted in a merger with a higher-mass cluster. They escape the merged cluster with relatively low velocities typical of the cluster interaction and thus of the larger scale velocity dispersion, similarly to the observed stars. $N$-body simulations of cluster mergers predict a sizeable population of low velocity ($\le$ 20 km s$^{-1}$), high-mass stars at distances of > 20 pc from the cluster. High-mass clusters in which gas poor mergers are frequent would be expected to commonly have halos of young stars, including high-mass stars, that were actually formed in a cluster environment.

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William E. Lucas, Matus Rybak, Ian A. Bonnell, Mark Gieles. 2017-11-27. A clustered origin for isolated massive stars. https://doi.org/10.1093/mnras%2Fstx2997

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