Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-25T07:35:32.871Z Has data issue: false hasContentIssue false

Asymmetric X-ray Pulsar Beam Emission

Published online by Cambridge University Press:  25 April 2016

Whayne E. P. Padden
Affiliation:
Department of Theoretical Physics, University of Sydney
Michelle C. Storey
Affiliation:
Department of Theoretical Physics, University of Sydney

Abstract

Many of the X-ray pulsars for which X-ray lightcurves have been presented in the literature exhibit asymmetric emission beams. We postulate the existence of an off-centre magnetic dipole field embedded in the rotating neutron star and show that such a field leads to varying rates of matter transfer between an accretion dise and the neutron star surface, over a rotation period. Assuming that the accretion rate onto the surface is simply related to the luminosity, we show that most of the observed asymmetries can be accounted for by this mechanism.

Type
Contributions
Copyright
Copyright © Astronomical Society of Australia 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arons, J., Barnard, D. J., Klein, R. I., McKee, C. F., Padritz, R. E.and Lea, S. M., (1984), in ‘High Energy Transients in Astrophysics’, AIP Conf. Proc. No. 115, ed. Woosley, S. Basko, M. M.and Sunyaev, R. A., 1975, Astron. Astrophys., 42, 311.Google Scholar
Basko, M. M.and Sunyeav, R. A., 1976, Mon. Not. R. Astron. Soc, 175, 395.CrossRefGoogle Scholar
Blandford, R. D., Applegate, J. H.and Hernquist, L., 1983, Mon. Not. R. Astron. Soc, 204, 1025.Google Scholar
Borner, G., 1980, Phys. Rep., 60, 151.Google Scholar
Ghosh, P. and Lamb, F. K., 1978, Astrophys. J. Lett., 223, L83.Google Scholar
Ghosh, P. and Lamb, F. K., 1979, Astrophys. J., 232, 259.Google Scholar
Kirk, J. G., 1986, Astron. Astrophys., 158, 305.Google Scholar
Kirk, J. G., Melrose, D. B.and Peters, J. G., 1984, Proc. Astron. Soc. Aust., 5, 478.CrossRefGoogle Scholar
Kirk, J. G.and Melrose, D. B., 1986, Astron. Astrophys., 156, 277.Google Scholar
Kirk, J. G., Nagel, W. and Storey, M. C., 1986, In preparation.Google Scholar
Langer, S. H.and Rappaport, S., 1982, Astrophys. J., 257, 733.Google Scholar
Melrose, D. B.and Kirk, J. G., 1986, Astron. Astrophys., 156, 268.Google Scholar
Pringle, J. E.and Rees, M. J., 1972, Astron. Astrophys., 21, 1.Google Scholar
Pringle, J. E., 1981, Annu. Rev. Astron. Astrophys., 19, 137.Google Scholar
Rappaport, S. and Joss, P. C., 1983, in ‘Accretion Driven Stellar X-ray Sources’ eds. Lewin, W. H. G. and Van Den Heuvel, E. P. S., (Cambridge University Press).Google Scholar
Trumper, J., Pietsch, W., Reppin, C., Voges, W., Straubert, R. and Kendziorra, E., 1978, Astrophys. J. Lett., 219, L105.CrossRefGoogle Scholar
Voges, W., Pietsch, W., Reppin, C., Trumper, J., Kendziorra, E. and Straubert, R., 1982, Astrophys. J., 263, 803.Google Scholar
Wang, Y. M.and Frank, J., 1981, Astron. Astrophys., 93, 255.Google Scholar
White, N. E., Swank, J. H.and Holt, S. S., 1983, Astrophys. J., 270, 711.Google Scholar