Probing the role of dynamical friction in shaping the BSS radial distribution. I. semi-analytical models and preliminary n-body simulations

P. Miocchi, M. Pasquato, B. Lanzoni, F. R. Ferraro, E. Dalessandro, E. Vesperini, E. Alessandrini, Y. W. Lee

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We present semi-analytical models and simplified N-body simulations with 104 particles aimed at probing the role of dynamical friction (DF) in determining the radial distribution of blue straggler stars (BSSs) in globular clusters. The semi-analytical models show that DF (which is the only evolutionary mechanism at work) is responsible for the formation of a bimodal distribution with a dip progressively moving toward the external regions of the cluster. However, these models fail to reproduce the formation of the long-lived central peak observed in all dynamically evolved clusters. The results of N-body simulations confirm the formation of a sharp central peak, which remains as a stable feature over time regardless of the initial concentration of the system. In spite of noisy behavior, a bimodal distribution forms in many cases, with the size of the dip increasing as a function of time. In the most advanced stages, the distribution becomes monotonic. These results are in agreement with the observations. Also, the shape of the peak and the location of the minimum (which, in most of cases, is within 10 core radii) turn out to be consistent with observational results. For a more detailed and close comparison with observations, including a proper calibration of the timescales of the dynamical processes driving the evolution of the BSS spatial distribution, more realistic simulations will be necessary.

    Original languageEnglish (US)
    Article number44
    JournalAstrophysical Journal
    Volume799
    Issue number1
    DOIs
    StatePublished - Jan 20 2015

    Keywords

    • analytical
    • blue stragglers
    • general
    • globular clusters
    • kinematics and dynamics
    • methods
    • methods
    • numerical
    • stars

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

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