2012/10/31 by Michiko S. Fujii, M. S. Fujii, Simon Portegies Zwart +1 · 39 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Collision #Core (optical fiber) #Physics #Star cluster #Stars #Stellar collision #Stellar evolution #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/sts673
published in Monthly Notices of the Royal Astronomical Society 430(2), 1018-1029 (Oxford University Press) · 13 pages. 16 figures, 3 tables, accepted for MNRAS
openalex publication_date 2013/01/24 · arxiv created 2014/06/06 · arxiv updated 2015/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recent simulations and observations suggest that star clusters form via the assembling of smaller subclusters. Because of their short relaxation time, subclusters experience core collapse much earlier than virialized solo clusters, which have similar properties of the merger remnant of the assembling clusters. As a consequence, it seems that the assembling clusters result in efficient multiple collisions of stars in the cluster core. We performed a series of N-body simulations of ensemble and solitary clusters including stellar collisions and found that the efficiency of multiple collisions between stars is suppressed if subclusters assemble after they experience core collapse individually. In this case, subclusters form their own multiple collision stars which experienced a few collisions, but they fail to collide with each other after their host subclusters assemble. The multiple collision stars scatter each other and escape, and furthermore the central density of the remnant clusters had already been depleted for the stars to experience more collisions. On the other hand, if subclusters assemble before they experience core collapse, the multiple collisions of stars proceed efficiently in the remnant cluster, and the collision products are more massive than virialized solo clusters and comparable in mass to cold solo clusters.