Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2S040


Pfalzner, Susanne (Max-Plank-Institut für Radioastronomie, Bonn)
Steinhausen, Manuel (Max-Plank-Institut für Radioastronomie, Bonn)

Most, if not all, stars form in a clustered environment and are initially surrounded by a gas-dust disc. These discs are dispersed within only a few Myr with the actual average disc dispersal time depending on the density of the cluster environment. Basically denser clusters lead to faster disc dispersal. The main two mechanisms considered as the reason for this environmentally induced disc destruction are tidal stripping by stellar encounters and photo-evaporation caused by the radiation from massive stars. Both mechanisms lead to the observed reduction in disc frequencies close to the central massive stars. So disc frequencies allow no distinction which of the two mechanisms dominate environmental-induced disc destruction. Here we want to suggest a method that allows to determine whether photo-evaporation or encounters is the dominant external disc destruction mechanism. It is demonstrated that comparing the average velocity and the velocity dispersion of stars with and without disc signature would be a reliable way to determine whether photo-evaporation or encounters are the main source of external disc destruction in dense clusters.

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