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Department of Physics

Staff profile

Publication details for Prof Martin Ward

King, A. R. Davies, M. B. Ward, M. J. , Fabbiano, G. & Elvis, M. (2001). Ultraluminous x-ray sources in external galaxies. Astrophysical Journal: Letters 552(2): L109-L112.

Author(s) from Durham


We investigate models for the class of ultraluminous nonnuclear X-ray sources (i.e., ultraluminous compact X-ray sources [ULXs]) seen in a number of galaxies and probably associated with star-forming regions. Models in which the X-ray emission is assumed to be isotropic run into several difficulties. In particular, the formation of sufficient numbers of the required ultramassive black hole X-ray binaries is problematic, and the likely transient behavior of the resulting systems is not in good accord with observation. The assumption of mild X-ray beaming suggests instead that ULXs may represent a short-lived but extremely common stage in the evolution of a wide class of X-ray binaries. The best candidate for this is the phase of thermal-timescale mass transfer that is inevitable in many intermediate- and high-mass X-ray binaries. This in turn suggests a link with the Galactic microquasars. The short lifetimes of high-mass X-ray binaries would explain the association of ULXs with episodes of star formation. These considerations still allow the possibility that individual ULXs may contain extremely massive black holes.


Abramowicz, M. A., Calvani, M., & Nobili, L. 1980, ApJ, 242, 772
Baraffe, I., Heger, A., & Woosley, S. E. 2001, ApJ, 550, 890
Belloni, T., Me´ndez, M., King, A. R., van der Klis, M., & van Paradijs, J.
1997, ApJ, 488, L109
Charles, P. 1998, in Theory of Black Hole Accretion Disks, ed. M. A. Abramowicz,
G. Bjornsson, & J. E. Pringle (Cambridge: Cambridge Univ. Press),
Dubus, G., Charles, P. A., Long, K., & Hakala, P. J. 1997, ApJ, 490, L47
Fabbiano, G. 1989, ARA&A, 27, 87
Fabbiano, G., Zezas, A., & Murray, S. S. 2001, ApJ, in press
Frank, J., King, A. R., & Raine, D. J. 1992, Accretion Power in Astrophysics
(2d ed.; Cambridge: Cambridge Univ. Press), chap. 4
Ho, L., Filippenko, A. V., Sargent, W. L., & Peng, C. Y. 1997, ApJS, 112,
Jaroszynski, M., Abramowicz, M. A., & Paczyn´ski, B. 1980, Acta Astron.,
30, 1
Kaaret, P., Prestwich, A. H., Zezas, A., Murray, S. S., Kim, D.-W., Kilgard,
R. E., Schlegel, E. M., & Ward, M. J. 2001, MNRAS, 321, L29
Kalogera, V., & Webbink, R. F. 1996, ApJ, 458, 301
King, A. R. 1988, QJRAS, 29, 1
———. 2000, MNRAS, 315, L33
King, A. R., & Begelman, M. C. 1999, ApJ, 519, L169
King, A. R., Kolb, U., & Burderi, L. 1996, ApJ, 464, L127
King, A. R., & Ritter, H. 1998, MNRAS, 293, L42
King, A. R., & Ritter, H. 1999, MNRAS, 309, 253
Kolb, U., Davies, M. B., King, A. R., & Ritter, H. 2000, MNRAS, 317, 438
Kubota, A., Mizuno, T., Makishima, K., Fukazawa, Y., Kotoku, J., Ohnishi,
T., & Tashiro, M. 2001, ApJ, 547, L119
Kulkarni, S. R., Hut, P., & McMillan, S. 1993, Nature, 364, 421
La Parola, V., Peres, G., Fabbiano, G., Kim, D.-W., & Bocchino, F. 2001,
ApJ, in press
Lee, H. M. 1995, MNRAS, 272, 605
Lee, M. H. 1993, ApJ, 418, 147
Makishima, K., et al. 2000, ApJ, 535, 632
Matsumoto, H., Tsuru, T. G., Koyama, K., Awaki, H., Canizares, C. R., Kawai,
N., Matsushita, S., & Kawabe, R. 2001, ApJ, 547, L25
Matsushita, S., Kawabe, R., Matsumoto, H., Tsuru, T., Kohno, K., Morita, K.,
Okumura, S. K., & Vila-Vilaro, B. 2000, ApJ, 545, 107
Mirabel, I. F., & Rodrı´guez, L. F. 1999, ARA&A, 37, 409
Papaloizou, J. C. B. 1973, MNRAS, 162, 143
Podsiadlowski, Ph., & Rappaport, S. A. 2000, ApJ, 529, 946
Ritter, H. 1999, MNRAS, 309, 360
Roberts, T., & Warwick, R. 2000, MNRAS, 315, 98
Sigurdsson, S., & Hernquist, L. 1993, Nature, 364, 423
Stothers, R. B., & Chin, C. W. 1999, ApJ, 522, 960
White, N. E., & Carpenter, G. F. 1978, MNRAS, 183, 11P
Zezas, A., Georgantopoulos, I., & Ward, M. J. 1999, MNRAS, 308, 302.