The formation and evolution of very massive stars in dense stellar systems

TL;DR

This paper introduces a new computational scheme for modeling the evolution of very massive stars in dense stellar systems, highlighting their role in black hole formation and stellar collisions.

Contribution

It presents a computationally efficient evolutionary scheme for very massive stars integrated into an N-body code, enabling studies of black hole formation in dense clusters.

Findings

Formation of intermediate and stellar mass black holes in starburst regions

Impact of stellar wind mass loss on the fate of very massive stars

Successful implementation of the scheme in the 'Youngbody' N-body code

Abstract

The early evolution of dense stellar systems is governed by massive single star and binary evolution. Core collapse of dense massive star clusters can lead to the formation of very massive objects through stellar collisions ($M\geq$ 1000 \msun). Stellar wind mass loss determines the evolution and final fate of these objects, and decides upon whether they form black holes (with stellar or intermediate mass) or explode as pair instability supernovae, leaving no remnant. We present a computationaly inexpensive evolutionary scheme for very massive stars that can readily be implemented in an N-body code. Using our new N-body code 'Youngbody' which includes a detailed treatment of massive stars as well as this new scheme for very massive stars, we discuss the formation of intermediate mass and stellar mass black holes in young starburst regions. A more detailed account of these results can be found in Belkus et al. 2007.