SCYON Abstract

Received on February 5 2001

Impact of Gas Removal on the Evolution of Embedded Clusters

Authors	Christian Boily¹, Pavel Kroupa²
Affiliation	¹ University of Heidelberg ² University of Kiel
Accepted by	Modes of Star Formation, E.Grebel, W.Brandner (eds), ASP Conf. Ser., in press
Contact	cmb@ari.uni-heidelberg.de, pavel@astrophysik.uni-kiel.de
URL	http://xxx.uni-augsburg.de/abs/astro-ph/0102024
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Abstract

We study both analytically and numerically the disruptive effect of instantaneous gas removal from an embedded cluster. We setup a calculation based on the stellar velocity distribution function, to compute the fraction of stars that remain bound once the cluster has ejected the gas and is out of equilibrium. We find tracks of bound mass-fraction vs star formation efficiency similar to those obtained with N-body calculations. We use these to argue that embedded clusters must develop high-binding energy cores if they are to survive as bound clusters despite a star formation rate as low as 20% or lower suggested by observations.