Powered by OpenAIRE graph
Found an issue? Give us feedback
addClaim

This Research product is the result of merged Research products in OpenAIRE.

You have already added 0 works in your ORCID record related to the merged Research product.

Dynamics of Dense Stellar Systems Including the Effects of Stellar Collisions

Authors: Hyung Mok Lee;

Dynamics of Dense Stellar Systems Including the Effects of Stellar Collisions

Abstract

Dynamical evolution of dense stellar systems is followed by integrating Fokker-Planck equation including successive mergers between stars. We have assumed that all the tidal captures lead to mergers. The initial cluster is assumed to be a single component Plummer model with mass of individual stars being 0.7 M⊙. The highest mass that is allowed to form through successive mergers in our model is 32 × 0.7M⊙ =22.4 M⊙. The stellar evolution is simulated by removing stars from the cluster assuming that the stellar material escapes as the star finishes the evolution. We have estimated the number of stars that evolve off per unit time using “evolution function” that depends on the mean age and lifetime. The mean ages are estimated from the rates of formation of stars (through merger). While the formation of massive stars leads to the acceleration of core collapse through mass segregation, the indirect heating effect due to stellar evolution makes the core collapse slow. The net effect depends on the initial conditions. The number of high mass stars depends sensitively on the cluster parameters. Core collapse is usually found to be terminated by the indirect heating effect of evolution of moderate mass stars (mainly 2.8 or 5.6 M⊙ in our models). The maximum number stars in highest mass bin (i.e., M=22.4 M⊙) varies from unity to an order of 101 depending on exact initial conditions for the models appropriate for the Galactic center. These numbers are too small to explain the observed HeI emission line stars which are interpreted as envelope stripped high mass (20~ 40 M⊙) stars. However, if the ejected material from the final stage of stellar evolution can form stars efficiently instead of escaping from the potential well of the stellar system, more high mass stars can be found. The presence of massive black hole in the center would also boost the merger rates.

Related Organizations
  • BIP!
    Impact byBIP!
    citations
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    5
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
citations
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
5
Average
Average
Average
Upload OA version
Are you the author? Do you have the OA version of this publication?