Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T05:13:01.513Z Has data issue: false hasContentIssue false

X-ray Observations of Crab-Like Supernova Remnants

Published online by Cambridge University Press:  04 August 2017

R. H. Becker*
Affiliation:
Virginia Polytechnic Institute and State University

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

On the basis of extensive radio surveys of the galactic plane, approximately 140 sources of diffuse radio emission have been classified as supernova remnants (SNR). Using spectral index and spatial distribution as the primary selection criteria, these have been subdivided into two groups, “shell” and “Crab-like”. In each case, the radio emission is assumed to be of non-thermal origin. The two distinct morphologies arise from two distinct energy sources. For shell remnants, the energy is drawn from the reservoir of kinetic energy in the expanding shock front; in Crab-like remnants, the energy is drawn from the rotational kinetic energy of a central stellar remnant.

These two classes of remnants differ significantly in their x-ray emission. With few exceptions, radio shell remnants emit thermal x-rays from shock heated gas which is itself distributed in a shell. Crab-like sources (as defined by their radio properties) emit synchrotron x-rays in a centrally-peaked spatial distribution. Presumably, the x-ray emission from these objects is an extension of the radio spectrum. Crab-like sources have a high probability of containing a compact (unresolved) source of x-ray emission which in analogy to the Crab Nebula, is identified as the central stellar remnant.

The general absence of either compact x-ray sources or Crab-like diffuse nebulae within shell sources indicates that active pulsars are not usually formed in SN events which eventually form shell sources. However, there are several examples of remnants which share both shell and Crab-like characteristics so we cannot rule out an evolutionary connection between these two classes of SNR.

Type
III. Center Filled Morphologies
Copyright
Copyright © Reidel 1983 

References

Andrews, M. P., Basart, J. F., Lamb, R. C., and Becker, R. H. 1982. Ap. J. (Letters) in press.Google Scholar
Angerhofer, P. C., Strom, R. G., Velusamy, T., and Kundu, M. R. 1981. Astron. Astrophys. 94, 313 Google Scholar
Becker, R. H. and Szymkowiak, A. E., 1981, Ap. J. (Letters) 248, L23.CrossRefGoogle Scholar
Becker, R. H. and Kundu, M. R. 1976, Ap. J. 204, 427.CrossRefGoogle Scholar
Becker, R. H., Helfand, D. J., and Szymkowiak, A. E. 1932, Ap. J. J. 255, 557.Google Scholar
Caswell, J. L. Milne, D. K., and Wellington, K. J. 1981 MNRAS, 195, 39.Google Scholar
Duin, R. M., Israel, F. P., Dickel, J. R., and Seaquist, E. R. 1975, Astron. Astrophys. 38, 461. [Pacini, F. and Salvati, M. 1973, Ap. J. 186, 249.]Google Scholar
Giacconi, R. et al. 1979, Ap. J. 230, 540.Google Scholar
Goldreich, P. and Julian, W. H. 1969. Ap. J. 197, 869.CrossRefGoogle Scholar
Milne, D. K., Goss, W. M., Haynes, R. F., Wellington, K. J., Caswell, J. L., and Skellern, D. J. 1979. MNRS 188, 437.Google Scholar
Pravdo, S.H. et al. 1976, Ap. J. (Letters) 203, L67.Google Scholar
Seward, F., Grindlay, J., Seaquist, E., and Gilmore, W. 1980. Nature 287, 806.Google Scholar
Seward, F. D. and Harnden, F. R. 1982 preprint.Google Scholar
Weiler, K. W. and Seielstad, G. A. 1971. Ap. J. 163, 455.CrossRefGoogle Scholar
Weiler, K. W. and Panagia, N. 1980. Astron. Astrophys. 90, 269.Google Scholar
Weiler, K. W. and Shaver, P. A. 1978. Astron. Astrophys. 70, 389.Google Scholar
Wilson, A. S. 1980. Ap. J. (Letters) 241, L19.Google Scholar