천문학회지 (Journal of The Korean Astronomical Society)

  • 제46권4호
  • /
  • Pages.173-181
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  • 2013
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  • 1225-4614(pISSN)
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  • 2288-890X(eISSN)
한국천문학회 (The Korean Astronomical Society)
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DARK MATTER CONTENT IN GLOBULAR CLUSTER NGC 6397

  • Shin, Jihye (Department of Astronomy and Space Science, Kyung Hee University) ;
  • Kim, Sungsoo S. (Department of Astronomy and Space Science, Kyung Hee University) ;
  • Lee, Young-Wook (School of Space Research, Kyung Hee University)
  • 투고 : 2013.06.20
  • 심사 : 2013.07.29
  • 발행 : 2013.08.31
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초록

We trace the dynamical evolution of dark matter (DM) content in NGC 6397, one of the native Galactic globular clusters (GCs). The relatively strong tidal field (Galactocentric radius of ~ 6 kpc) and short relaxation timescale (~0.3 Gyr) of the cluster can cause a significant amount of DM particles to evaporate from the cluster in the Hubble time. Thus, the cluster can initially contain a non-negligible amount of DM. Using the most advanced Fokker-Planck (FP) method, we calculate the dynamical evolution of GCs for numerous initial conditions to determine the maximum initial DM content in NGC 6397 that matches the present-day brightness and velocity dispersion profiles of the cluster. We find that the maximum allowed initial DM mass is slightly less than the initial stellar mass in the cluster. Our findings imply that NGC 6397 did not initially contain a significant amount of DM, and is similar to that of NGC 2419, the remotest and the most massive Galactic GC.

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피인용 문헌

  1. Indirect probes of dark matter and globular cluster properties from dark matter annihilation within the coolest white dwarfs vol.91, pp.10, 2015, https://doi.org/10.1103/PhysRevD.91.103514