Collisions Between Single Stars in Dense Clusters: Runaway Formation of a Massive Object

Marcus Freitag, M A Guerkan, Frederic A Rasio

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Using Monte Carlo codes, we follow the collisional evolution of clusters in a variety of scenarios. We consider the conditions under which a cluster of main-sequence stars may undergo rapid core collapse due to mass segregation, thus entering a phase of runaway collisions, forming a very massive star (VMS, M* > 1000M⊙) through repeated collisions between single stars. Although collisional mass loss is accounted for realistically, we find that a VMS forms even in proto-galactic nuclei models with a high velocity dispersion (many 100 kms−1). Such a VMS may be a progenitor for an intermediate-mass black hole (M� ≥ 100M⊙). In contrast, in galactic nuclei hosting a central massive black hole, collisions are found to be disruptive. The stars which are subject to collisions are progressively ground down by high-velocity collisions and a merger sequence appears impossible.
Original languageEnglish (US)
Title of host publicationMassive Stars in Interactive Binaries
EditorsNicole St.Louis, Anthony F L Moffat
PublisherAstronomical Society of the Pacific
Number of pages7
ISBN (Electronic)978-1-583813-01-0
ISBN (Print)978-1-583812-35-8
StatePublished - 2007

Publication series

NameAstronomical Society of the Pacific Conference Series


Dive into the research topics of 'Collisions Between Single Stars in Dense Clusters: Runaway Formation of a Massive Object'. Together they form a unique fingerprint.

Cite this