Journal of The Korean Astronomical Society (천문학회지)

The Korean Astronomical Society (한국천문학회)
권호 표지

VELOCITY DISTRIBUTION OF DARK MATTER GALACTIC HALO

  • OH K. S. (Department of Astronomy and Space Science Chungnam National University)
  • Published : 1997.04.01
Download PDF
⟨ Previous Next ⟩

Abstract

We investigate the velocity distribution of dark matter in the disk of a galaxy like the Milky Way at the solar radius. Using N-body simulations with the total mass and z-component of angular momentum conserved, we calculate the response of a dissipationless dark matter galactic halo during the dissipational collapse of the baryonic matter in spiral galaxy formation. The initial distribution of dark matter and baryonic particles is assumed to be a homogeneous mixture based on a King model. The baryonic matter is assumed to contract, forming the final luminous components of the galaxy, namely the disk and, in some cases, a bulge and central point. Both slow and fast growth of the luminous components are considered. We find that the velocity distribution of dark matter particles in a reference frame rotating slowly about the galaxy center in the plane of the disk is similar to a Maxwellian, but it is somewhat boxier, being flatter at the peak and truncated in the tails of the distribution. We tabulate parameters for the best-fitting Maxwellian and modified-Maxwellian distributions. There is no significant difference between slow collapse and fast collapse for all these results. We were unable to detect any effect of disk formation on the z-dependence of the dark matter density distribution.

Keywords

References

  1. Ap. J. v.236 Aarseth, S. J.;Fall, S. M.
  2. Multiple Time Scales Aarseth, S. J.;J. W. Brackhill(ed.);B. I. Cohen(ed.)
  3. Ap. J. (Letters) v.258 Bahcall, J. N.;Schmidt, M.;Soneira, R. M.
  4. Ap. J. v.265 Bahcall, J. N.;Schmidt, M.;Soneira, R. M.
  5. Ap. J. Suppl. v.44 Bahcall, J. N.;Soneira, R. M.
  6. M. N. R. A. S. v.211 Barnes, J.;White, S. D. M.
  7. Nearly Normal Galaxies Barnes, J.;S. Faber(ed.)
  8. Ap. J. v.319 Barnes, J.;Efstathiou, G.
  9. Ap. J. v.151 Becklin, E. E.;Neugebauer, G.
  10. Ap. J. v.301 Blumenthal, G. R.;Faber, S. M.;Flores, R.;Primack, J. R.
  11. IAU Symposium 190, Large Scale Structure of the Universe Blumenthal, G. R.;J. Audouze(et al.)(ed.)
  12. Ph. D. Thesis, Groningen Bosma, A.
  13. Ap. J. v.251 Caldwell, J. A. R.;Ostriker, J. P.
  14. Astron. J. v.101 Casertano, S.;van Gorkom, J. H.
  15. Astron. J. v.82 de Vaucouleurs, G.
  16. Astron. J. v.83 de Vaucouleurs, G.;Buta, R.
  17. Phys. Rev. v.D33 Drukier, A.;Freese, K.;Spergel, D.
  18. M. N. R. A. S. v.186 Efstathiou, G.;Jones, B. J. T.
  19. M. N. R. A. S. v.193 Fall, S. M.;Efstathiou, G.
  20. Ap. J. v.160 Freeman, K.
  21. Phys. Rev. v.D37 Freese, K.;Frieman, J.;Gould, A.
  22. Nature v.317 Frenk, C. S.;White, S. D. M.;Efstathiou, G.;Davis, M.
  23. Nonparametric Methods for Quantitative Analysis Gibbons, J. D.
  24. Ap. J. v.328 Hoffman, Y.
  25. AP. J. v.377 Katz, N.;Gunn, J. E.
  26. Astron. J. v.71 King, I. R.
  27. Astr. Ap. v.11 King, I. R.
  28. Ph. D. thesis, Univ. California Oh, K. S.
  29. Astr. Ap. v.11 Peebles, P. J. E.
  30. Ann. Rev. Nucl. Part. Sci. v.38 Primack, J. R.;Seckel, D.;Sadoulet, B.
  31. Nature v.322 Quinn, P. J.;Salmon, J. K.;Zurek, W. H.
  32. Ap. J. v.331 Quinn, P. J.;Zurek, W.H.
  33. Ap. J. v.238 Rubin, V. C.;Ford, W. K.;Thonnard, N.
  34. Ap. J. v.261 Rubin, V. C.;Ford, W. K.;Thonnard, N.
  35. Ap. J. v.289 Rubin, V. C.;Burstein, D.;Ford, W. K.;Thonnard, N.
  36. Ap. J. v.318 Ryden, B. S.;Gunn, J. E.
  37. Phys. Rept. v.bf187 Smith, P. F.;Lewin, J. D.
  38. Ap. J. v.138 Toomre, A.
  39. Astron. J. v.81 Young, P. J.