Contraction and Fragmentation of Magnetized Rotating Clouds and Formation of Binary Systems

  • Kohji Tomisaka
  • Masahiro N. Machida
  • Tomoaki Matsumoto


Using three-dimensional (3D) magnetohydrodynamical (MHD) nested-grid simulations, the fragmentation of a rotating magnetized molecular cloud core is studied. An isothermal rotating magnetized cylindrical cloud in hydrostatic balance is considered. We studied non-axisymmetric evolution of the cloud. It is found that non-axisymmetry hardly evolves in the early phase, but it begins to grow after the gas contracts and forms a thin disk. The disk formation and thus growth of non-axisymmetric perturbation are strongly promoted by rotation and magnetic field strength. We found two types of fragmentations: fragmentation from a ring and that from a bar. These two types of fragmentations occur in thin adiabatic cores with the thickness being smaller than 1/4 of the radial size. For the fragments to survive, they should be formed in a heavily elongated barred core or a flat round disk. In the models showing fragmentation, outflows from respective fragments are found as well as that driven by the rotating bar or the disk.


ISM: magnetic fields stars: formation ISM: jets and outflow stars: binary 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abt, H.A.: 1983, ARA,A 21, 343.ADSCrossRefGoogle Scholar
  2. Boss, A.P.: 1993, ApJ 410, 157.ADSCrossRefGoogle Scholar
  3. Boss, A.P.: 2002, ApJ 568, 743.ADSCrossRefGoogle Scholar
  4. Boss, A.P., Myhill, E.A.: 1995, Api 451, 218.ADSGoogle Scholar
  5. Duquennoy, A., Mayor, M.: 1991, A,A 248, 485.Google Scholar
  6. Fukuda, F., Hanawa, T.: 1999, ApJ 517, 226.ADSCrossRefGoogle Scholar
  7. Kroupa, P., Burkert, A.: 2001, Api 555, 945.ADSGoogle Scholar
  8. Larson, R.B.: 1969, MNRAS 145, 271.ADSGoogle Scholar
  9. Machida, M.N.: 2003, Binary Star Formation and Mass Outflow in the Molecular Cloud Core, PhD thesis, Hokkaido U.Google Scholar
  10. Matsumoto, T., Hanawa, T., Nakamura, F.: 1997, ApJ 478, 569.ADSCrossRefGoogle Scholar
  11. Matsumoto, T., Nakamura, F., Hanawa, T.: 1994, PASJ 46, 243.ADSGoogle Scholar
  12. Miyama, S.M., Hayashi, C., Narita, S.: 1984, Api 279, 621.ADSGoogle Scholar
  13. Nakamura, F., Hanawa, T.: 1997, ApJ 480, 701.ADSCrossRefGoogle Scholar
  14. Norman, M.L., Wilson, J.R., Barton, R.T.: 1980, Api 239, 968.ADSMathSciNetGoogle Scholar
  15. Stodólkiewicz, J.S.: 1963, Acta Astron. 13, 30.ADSzbMATHGoogle Scholar
  16. Tohline, J.E.: 1982, Fundam. Cosm. Phys. 8, 1.ADSGoogle Scholar
  17. Tomisaka, K.: 1995, Api 438, 226.ADSGoogle Scholar
  18. Tomisaka, K.: 1998, Api 502, L163.ADSGoogle Scholar
  19. Tomisaka, K.: 2000, Api 528, L41.ADSGoogle Scholar
  20. Tomisaka, K.: 2002, Api 575, 306.ADSGoogle Scholar
  21. Truelove, J.K., Klein, R.I., Mckee, C.F., Holliman, J.H., Howell, L.H., Greenough, J.A.: 1997, Api 489, L179.ADSGoogle Scholar
  22. Tsuribe, T., Inutsuka, S.: 1999, Api 523, LI55.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2004

Authors and Affiliations

  • Kohji Tomisaka
    • 1
  • Masahiro N. Machida
    • 1
  • Tomoaki Matsumoto
    • 2
  1. 1.Theoretical AstrophysicsNational Astronomical ObservatoryMitaka, TokyoJapan
  2. 2.Faculty of Humanity and EnvironmentHosei UniversityFujimi, Chiyoda-ku, TokyoJapan

Personalised recommendations