Evolution of Magnetic Fields in Bok Globules?

  • Sebastian Wolf
  • Ralf Launhardt
  • Thomas Henning


We study the influence and structure of the magnetic field in the early phases of low-mass star formation using polarization maps of Bok globules at a wavelength of 850 μm, obtained with the Submillimeter Common-User Bolometer Array (SCUBA) at the James Clerk Maxwell Telescope (JCMT). We discuss observations of the following sources: CB 26—a small globule with a nearly dispersed dense core and a young and large circumstellar disk, CB 54—a large globule with a massive dense core and a deeply embedded young stellar cluster, and B 335, CB 230, and CB 244—three nearby, relatively isolated small globules with low-mass protostellar cores.

We find strongly aligned polarization vectors in the case of CB 26, B 335, and CB 230, whereas the vector orientations in the case of CB 54 and CB 244 are more or less randomly distributed. The degree of polarization, amounting to several percent, was found to decrease toward the center in each source. Assuming dichroic emission by aligned non-spherical grains as the polarization mechanism, where the magnetic field plays a role in the alignment process, we derive magnetic field strengths and structures from the observed polarization patterns.

We compare the magnetic field topology with the morphology and outflow directions of the globules. In the Class 0 sources B 335, CB 230, and CB 244, the magnetic field is oriented almost perpendicular to the ouflow direction. In contrast, the inclination between outflow axis and magnetic field direction is much more moderate (36°) in the more evolved Class I source CB26.


magnetic fields polarization individual objects CB 26 CB 54 CB 230 CB 244 B 335 magnetic fields submillimeter 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Berry, D.S. and Gledhill, T.M.: 1999, Starlink User Note 223.Google Scholar
  2. Brand, J. and Blitz, L.: 1993, AandA 275, 67.Google Scholar
  3. Chandler, C.J., Gear, W.K., Sandell, G., Hayashi, S., Duncan, W.D., Griffin, M.J. and Hazella, S.: 1990, MNRAS 243, 330.ADSGoogle Scholar
  4. Chandler, C.J. and Sargent, A.I.: 1993, ApJ 414, L29.ADSCrossRefGoogle Scholar
  5. Chandrasekhar, S. and Fermi, E.: 1953, ApJ 118, 113.ADSCrossRefMathSciNetGoogle Scholar
  6. Draine, B.T. and Weingartner, J.C.: 1997, Api 480, 633.ADSGoogle Scholar
  7. Fiege, J.D. and Pudritz, R.E.: 2000a, ApJ 534, 291.ADSCrossRefGoogle Scholar
  8. Fiege, J.D. and Pudritz, R.E.: 2000b, MNRAS 311, 105.ADSCrossRefGoogle Scholar
  9. Frerking, M.A., Langer, W.D. and Wilson, R.W.: 1987, Api 313, 320.ADSGoogle Scholar
  10. Glenn, J., Walker, C.K. and Young, E.T.: 1999, ApJ 511, 812.ADSCrossRefGoogle Scholar
  11. Greaves, J.S., Holland, W.S., Minchin, N.R., Murray, A.G. and Stevens, J.A.: 1999, AandA 334, 668.Google Scholar
  12. Henning, Th., Wolf, S., Launhardt, R. and Waters, R.: 2001, Api 561, 871.ADSGoogle Scholar
  13. Hirano, N., Kameya, O., Nakayama, M. and Takakubo, K.: 1988, ApJI 327,L69.Google Scholar
  14. Holland, W.S., Robson, E.I., Gear, W.K., Cunningham, C.R., Lightfoot, J.F., Jennes, T., Ivison, R.J., Stevens, J.A., Ade, P.A.R., Griffin, M.J., Duncan, W.D., Murphy, J.A. and Naylor, D.A.: 1999, MNRAS 303, 659.ADSCrossRefGoogle Scholar
  15. Houde, M., Bastien, P., Dotson, J.L., Dowell, C.D., Hildebrand, R.H., Peng, R., Phillips, T.G., Vaillancourt, J.E. and Yoshida, H.: 2002, Api 569, 803.ADSGoogle Scholar
  16. Jenness, T. and Lightfoot, J.F.: 1998, in: R. Albrecht, R.N. Hook and H.A. Bushouse (eds.), ASP Conference Series 145, Astronomical Data Analysis Software and Systems VII, ASP, San Francisco, p. 216.Google Scholar
  17. Keene, J., Davidson, J.A., Harper, D.A., Hildebrand, R.H., Jaffe, D.T., Loewenstein, R.F., Low, F.J. and Pernic, R.: 1983, Apil 274, L43.Google Scholar
  18. Kun, M.: 1998, Apis 115, 59.Google Scholar
  19. Launhardt, R.: 1996, Ph.D. Thesis, University of Jena.Google Scholar
  20. Launhardt, R.: 2001, in: Reipurth, B. and Zinnecker, H. (eds.), Birth and Evolution of Binary Stars, Proceedings of IAU Symposium No. 200, p. 117.Google Scholar
  21. Launhardt, R., Evans, N.J., Wang, Y., Clemens, D.P., Henning, Th. and Yun, J.L.: 1998, ApJSS 119, 59.Google Scholar
  22. Launhardt, R. and Henning, Th.: 1997, AandA 326, 329.Google Scholar
  23. Launhardt, R., Mezger, P.G., Haslam, C.G.T., Kreysa, E., Lemke, R., Sievers, A. and Zylka, R.: 1996, AandA 312, 569.Google Scholar
  24. Launhardt, R. and Sargent, A.: 2001, Api 562, L173.ADSGoogle Scholar
  25. Launhardt, R., Ward-Thompson, D. and Henning, Th.: 1997, MNRAS 288, L45.ADSCrossRefGoogle Scholar
  26. Matthews, B.C. and Wilson, C.D.: 2002, Api 574, 822.ADSGoogle Scholar
  27. Myers, P.C., Fuller, G.A., Goodman, A.A. and Benson, P.J.: 1991, ApJ 376, 561.ADSCrossRefGoogle Scholar
  28. Myers, P.C., Goodman, A.A., Gusten, R. and Heiles, C.: 1995, Api 442, 177.ADSGoogle Scholar
  29. Ryden, B.S.: 1996, Api 471, 822.ADSGoogle Scholar
  30. Tornita, Y., Saito, T. and Ohtani, H.: 1979, PASJ31, 407.Google Scholar
  31. Wang, Y., Evans, N.J.II, Zhou, S. and Clemens, D.P.: 1995, Api 454, 217.ADSGoogle Scholar
  32. Weintraub, D.A., Goodman, A.A. andAkeson, R.L.: 2000, in: V. Mannings, A.P. Boss and S.S. Russell (eds.), Protostars and Planets IV, Univ. Arizona Press, Tucson, p. 247.Google Scholar
  33. Wolf, S., Launhardt, R. and Henning, Th.: 2003, Api 592, 233.ADSGoogle Scholar
  34. Yun, J.L. and Clemens, D.P.: 1994a, ApiS 92, 145.ADSGoogle Scholar
  35. Yun, J.L. and Clemens, D.P.: 1994b, Ai 108, 612.ADSGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2004

Authors and Affiliations

  • Sebastian Wolf
    • 1
    • 2
  • Ralf Launhardt
    • 2
  • Thomas Henning
    • 2
  1. 1.California Institute of TechnologyPasadenaUSA
  2. 2.Max-Planck-Institut für AstronomieHeidelbergGermany

Personalised recommendations