Gas expulsion in highly substructured embedded star clusters
Journal article, 2018

We investigate the response of initially substructured, young, embedded star clusters to instantaneous gas expulsion of their natal gas. We introduce primordial substructure to the stars and the gas by simplistically modelling the star formation process so as to obtain a variety of substructure distributed within our modelled star-forming regions. We show that, by measuring the virial ratio of the stars alone (disregarding the gas completely), we can estimate how much mass a star cluster will retain after gas expulsion to within 10 per cent accuracy, no matter how complex the background structure of the gas is, and we present a simple analytical recipe describing this behaviour. We show that the evolution of the star cluster while still embedded in the natal gas, and the behaviour of the gas before being expelled, is crucial process that affect the time-scale on which the cluster can evolve into a virialized spherical system. Embedded star clusters that have high levels of substructure are subvirial for longer times, enabling them to survive gas expulsion better than a virialized and spherical system. By using a more realistic treatment for the background gas than our previous studies, we find it very difficult to destroy the young clusters with instantaneous gas expulsion. We conclude that gas removal may not be the main culprit for the dissolution of young star clusters.

galaxies: star clusters: general

methods: numerical

stars: formation

Author

Juan Pablo Farias Osses

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

M. Fellhauer

University of Concepcion

R. Smith

Korea Astronomy and Space Science Institute

R. Dominguez

University of Concepcion

J. Dabringhausen

Charles University

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 476 4 5341-5357

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Metallurgy and Metallic Materials

DOI

10.1093/mnras/sty597

More information

Latest update

9/6/2018 1