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Impact of Magnetic Fields on Fragmentation

Published online by Cambridge University Press:  13 May 2016

Alan P. Boss*
Affiliation:
Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, N. W., Washington, D. C. 20015–1305, U.S.A.

Abstract

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Fragmentation is the leading explanation for the formation of binary and multiple stars. However, nearly all three dimensional calculations of the collapse and fragmentation of dense molecular cloud cores have ignored the effects of magnetic fields, whereas magnetic fields are generally regarded to be a dominant force in molecular clouds. Three dimensional models of the collapse of clouds with frozen-in magnetic fields have shown that such clouds cannot fragment for a range of initial conditions. However, calculations that allow for magnetic field loss by am-bipolar diffusion have shown that fragmentation is possible for initially prolate or oblate, rotating, magnetically-supported cloud cores. The latter calculations rely on approximations that should be verified by more detailed, traditional magnetohydrodynamical codes. The most obvious effect of magnetic fields is to delay the onset of the collapse phase, but once collapse begins in earnest, fragmentation proceeds in much the same manner as in nonmagnetic clouds, with initially prolate clouds tending to form binary protostars, and with initially oblate clouds tending to form multiple protostars.

Type
IX. Theoretical Context - Detailed Calculations
Copyright
Copyright © Astronomical Society of the Pacific 2001 

References

André, P., Ward-Thompson, D., Motte, F. 1996, A&A, 314, 625.Google Scholar
Basu, S. 1997, ApJ, 485, 240.CrossRefGoogle Scholar
Basu, S. 1998, ApJ, 509, 229.CrossRefGoogle Scholar
Basu, S., Mouschovias, T. Ch. 1994, ApJ, 432, 720.CrossRefGoogle Scholar
Benz, W. 1984, A&A, 139, 378.Google Scholar
Bodenheimer, P. 1995, ARA&A, 33, 199.Google Scholar
Bodenheimer, P., Burkert, A., Klein, R. I., Boss, A. P. 2000, in Protostars and Planets IV, ed. Mannings, V. G., Boss, A. P., Russell, S. S. (University of Arizona Press: Tucson), 675.Google Scholar
Bodenheimer, P., Ruzmaikina, T., Mathieu, R. D. 1993, in Protostars & Planets III, ed. Levy, E. H., Lunine, J. I. (University of Arizona Press: Tucson), 367.Google Scholar
Boss, A. P. 1987, ApJ, 319, 149.CrossRefGoogle Scholar
Boss, A. P. 1988, Comm. Astrophys., 12, 169.Google Scholar
Boss, A. P. 1993, in The Realm of Interacting Binary Stars, ed. Sahade, J., McCluskey, G., Kondo, Y. (Kluwer: Dordrecht), 355.CrossRefGoogle Scholar
Boss, A. P. 1997, ApJ, 483, 309.CrossRefGoogle Scholar
Boss, A. P. 1998, ApJ, 501, L77.CrossRefGoogle Scholar
Boss, A. P. 1999, ApJ, 520, 744.CrossRefGoogle Scholar
Brandner, W., Alcalá, J. M., Kunkel, M., Moneti, A., Zinnecker, H. 1996, A&A, 307, 121.Google Scholar
Ciolek, G. E., Mouschovias, T. Ch. 1995, ApJ, 454, 194.CrossRefGoogle Scholar
Crutcher, R. M. 1999, ApJ, 520, 706.CrossRefGoogle Scholar
Dorfi, E. 1982, A&A, 114, 151.Google Scholar
Duchêne, G., Bouvier, J., Simon, T. 1999, A&A, 343, 831.Google Scholar
Duquennoy, A., Mayor, M. 1991, A&A, 248, 485.Google Scholar
Fiedler, R. A., Mouschovias, T. Ch. 1993, ApJ, 415, 680.CrossRefGoogle Scholar
Fischer, D. A., Marcy, G. W. 1992, ApJ, 396, 178.CrossRefGoogle Scholar
Ghez, A. M., Neugebauer, G., Matthews, K. 1993, AJ, 106, 2005.CrossRefGoogle Scholar
Goodman, A. A., Benson, P. J., Fuller, G. A., Myers, P. C. 1993, ApJ, 406, 528.CrossRefGoogle Scholar
Hujeirat, A., Camenzind, M., Yorke, H. W. 2000, A&A, 354, 1041.Google Scholar
Indebetouw, R., Zweibel, E. G. 2000, ApJ, 532, 361.CrossRefGoogle Scholar
Leinert, C., Zinnecker, H., Weitzel, N., Christou, J., Ridgway, S. T., Jameson, R., Haas, M., Lenzen, R. 1993, A&A, 278, 129.Google Scholar
Lizano, S., Shu, F. H. 1989, ApJ, 342, 834.CrossRefGoogle Scholar
Mouschovias, T. Ch. 1987, in Physical Processes in Interstellar Clouds, ed. Morfill, G. E., Scholer, M. (D. Reidel: Dordrecht), 453.CrossRefGoogle Scholar
Mouschovias, T. Ch. 1991, ApJ, 373, 169.CrossRefGoogle Scholar
Myers, P. C., Fuller, G. A., Goodman, A. A., Benson, P. J. 1991, ApJ, 376, 561.CrossRefGoogle Scholar
Nakamura, F., Hanawa, T. 1997, ApJ, 480, 701.CrossRefGoogle Scholar
Nakano, T. 1998, ApJ, 494, 587.CrossRefGoogle Scholar
Nakano, T., Umebayashi, T. 1988, Progr. Theor. Phys. Suppl., 96, 73.CrossRefGoogle Scholar
Ohashi, N., Hayashi, M., Ho, P. T. P., Momose, M., Tamura, M., Hirano, N., Sargent, A. I. 1997, ApJ, 488, 317.CrossRefGoogle Scholar
Petr, M. G., Du Foresto, V. C., Beckwith, S. V. W., Richichi, A., McCaughrean, M. J. 1998, ApJ, 500, 825.CrossRefGoogle Scholar
Phillips, G. J. 1986a, MNRAS, 221, 571.CrossRefGoogle Scholar
Phillips, G. J. 1986b, MNRAS, 222, 111.CrossRefGoogle Scholar
Phillips, G. J., Monaghan, J. J. 1985, MNRAS, 216, 883.CrossRefGoogle Scholar
Pringle, J. E. 1991, in The Physics of Star Formation and Early Stellar Evolution, ed. Lada, C. J., Kylafis, N. D. (Kluwer: Dordrecht), 437.CrossRefGoogle Scholar
Reipurth, B., Zinnecker, H. 1993, A&A, 278, 81.Google Scholar
Richichi, A., Leinert, C., Jameson, R., Zinnecker, H. 1994, A&A, 287, 145.Google Scholar
Shu, F. H. 1977, ApJ, 214, 488.CrossRefGoogle Scholar
Shu, F. H., Adams, F. C., Lizano, S. 1987, ARA&A, 25, 23.Google Scholar
Shu, F. H., Li, Z.-Y. 1997, ApJ, 475, 251.CrossRefGoogle Scholar
Simon, M., Ghez, A. M., Leinert, C. H., Cassar, L., Chen, W. P., Howell, R. R., Jameson, R. F., Matthews, K. 1995, ApJ, 443, 625.CrossRefGoogle Scholar
Stone, J. M., Norman, M. L. 1992, ApJS, 80, 791.CrossRefGoogle Scholar
Tafalla, M., Mardones, D., Myers, P. C., Caselli, P., Bachiller, R., Benson, P. J. 1998, ApJ, 504, 900.CrossRefGoogle Scholar
Tomisaka, K., Ikeuchi, S., Nakamura, T. 1988, ApJ, 326, 208.CrossRefGoogle Scholar
Tomisaka, K., Ikeuchi, S., Nakamura, T. 1990, ApJ, 362, 202.CrossRefGoogle Scholar
Truelove, J. K., Klein, R. I., McKee, C. F., Holliman, J. H., Howell, L. H., Greenough, J. A. 1997, ApJ, 489, L179.CrossRefGoogle Scholar
Ward-Thompson, D., Motte, F., André, P. 1999, MNRAS, 305, 143.CrossRefGoogle Scholar
Ward-Thompson, D., Scott, P. F., Hills, R. E., André, P. 1994, MNRAS, 268, 276.CrossRefGoogle Scholar
Williams, J. P., Myers, P. C. 1999, ApJ, 518, L37.CrossRefGoogle Scholar
Williams, J. P., Myers, P. C., Wilner, D. J., Di Francesco, J. 1999, ApJ, 513, L61.CrossRefGoogle Scholar