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Globular Cluster X-Ray Sources

Published online by Cambridge University Press:  30 March 2016

Jonathan E. Grindlay*
Affiliation:
Center for Astrophysics, Harvard and Smithsonian Observatories

Extract

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The discoveries of both steady and bursting X-ray sources in globular clusters have made them as interesting for high energy astrophysics and X-ray astronomy as they were for unlocking galactic structure in Shapley’ s day. Globular clusters are massive (˜ 105 M) spherical clusters of primarily low mass (⋞0.8 M) evolved stars and may be the oldest systems in the Galaxy. Thus when several globular clusters were tentatively identified as containing X-ray sources (Giacconi et al. 1974), it was apparent that either dynamical or evolutionary processes must be occurring among the ancient stars in globular clusters to produce the relatively short-lived X-ray sources. The existence of these X-ray sources has prompted considerable discussion as to their origin, since they exist with ˜100 times the probability per unit mass in globular clusters as in the Galaxy as a whole (Katz 1975; Clark 1975). They may be yet another example of X-ray binaries (e. g., Clark 1975; Fabian et al. 1975) or be due to accretion onto a single collapsed object (black hole) at the center of the cluster (Bahcall and Ostrlker 1975; Silk and Arons 1975). At present both of these classes of models are possible and generally consistent with the data, though each has its particular difficulties. We shall review the observational data and then the models in an effort to point out the present balance of evidence for the binary vs. black hole models as well as the most promising directions for future work. Given the possibly high incidence of X-ray bursters in globular clusters, our discussion will refer to both observations and recent models for bursters. While this review will primarily address the X-ray sources in globular clusters, it is obvious that their eventual understanding will contribute much to studies of globular clusters in general and will prompt future studies in particular areas.

Type
Joint Dicussions
Copyright
Copyright © Reidel 1977

References

Arp, H. C. 1965, in Galactic Structure , ed. Blaauw, A. and Schmidt, M. (Chicago: Univ. of Chicago Press), p. 401.Google Scholar
Babushkina, O. P., Bratolyubova-Tsulukidze, L. S., Kudryavtsev, M. I., Melioranskii, A. S., Savenko, I. A., and Yushkov, B. Yu. 1975, Sov. Astron. Lett., 1, 32.Google Scholar
Bancall, J. N., and Wolf, R. A. 1976, Ap. J., in press.Google Scholar
Bancall, J., and Ostriker, J. 1975, Nature, 256, 23.Google Scholar
Bancall, N. A., and Hausman, M. A. 1976, Ad. J. (Letters), 207, L181.CrossRefGoogle Scholar
Becker, R. H., Pravdo, S. H., Serlemitsos, P. J., and Swank, J. H. 1976, IAU Circ. No. 2953.Google Scholar
Canizares, C. R. 1975, Ap. J., 201, 589.Google Scholar
Canizares, C. R., and Neighbours, J. E. 1975, Ad. J. (Letters), 199, L97.Google Scholar
Clark, G. W. 1975, Ap. J. (Letters), 199, LI43.Google Scholar
Clark, G. W., Li, F. K., Canizares, C., Jernigan, G., Lewin, W. H. G. 1976, preprint.Google Scholar
Clark, G. W., Markert, T. H., and Li, F. K. 1975, Ap. J. (Letters), 199, L93.CrossRefGoogle Scholar
Cominsky, L., Forman, W., Jones, C., and Tananbaum, H. 1976, preprint.Google Scholar
Fabian, A. C., Pringle, J. E., and Rees, M. J. 1975, MNRAS, 172, 15P.CrossRefGoogle Scholar
Forman, W., and Jones, C. 1976, Ap. J. (Letters), 207, L177.CrossRefGoogle Scholar
Forman, W., Jones, C., and Tananbaum, H. 1976, Ap. J. (Letters), 207, L25.Google Scholar
Frank, J., and Rees, M. J. 1976, MNRAS, 176, 633.CrossRefGoogle Scholar
Giacconi, R., Murray, S., Gursky, H., Kellogg, E. M., Schreier, E., Matilsky, T., Koch, D., and Tananbaum, H. 1974, Ap. J. Suppl. No. 237, 27, 37.CrossRefGoogle Scholar
Grindlay, J. 1976, submitted to Ap. J. (Letters).Google Scholar
Grindlay, J., and Gursky, H. 1976, Ap. J. (Letters), in press.Google Scholar
Grindlay, J., and Liller, W. 1976, in preparation.Google Scholar
Grindlay, J., Gursky, H., Schnepper, H., Parsignault, D. R., Heise, J., Brinkman, A. C., and Schrijver, J. 1976a, Ap. J. (Letters), 201, L127.CrossRefGoogle Scholar
Grindlay, J., Schnepper, H., Schreier, E., Gursky, H., and Parsignault, D. R. 1976b, Ap. J. (Letters), 206, L23.CrossRefGoogle Scholar
Grindlay, J., Gursky, H., Parsignault, D. R., Heise, J., and Brinkman, A. C. 1976c, submitted to Ap. J. (Letters).Google Scholar
Gursky, H., and Schreier, E. 1974, IAU Symp. No. 67 on Variable Stars.CrossRefGoogle Scholar
Heise, J., Brinkman, A. C, den Boggende, A. J. F., Parsignault, D. R., Grindlay, J., and Gursky, H. 1976, Nature, 261, 562.Google Scholar
Hesser, J. E., and Hartwick, F. D. A. 1976, Ap. J., 203, 97.Google Scholar
Hills, J. G. 1975, Astron. J., 80, 1075.Google Scholar
Jernigan, G. 1976, private communication.Google Scholar
Johnson, H. M., Catura, R. C., Charles, P. A., and Sanford, P. W. 1976, preprint.Google Scholar
Jones, C. 1976, preprint.Google Scholar
Julien, P., and Grindlay, J. 1976, in preparation.Google Scholar
Katz, J. I. 1975, Nature, 253, 698.Google Scholar
King, I. R., and Illingworth, G. 1976, talk at IAU Mtgs., Grenoble.Google Scholar
Kleinman, D. E., Kletnman, S. G., and Wright, E. L. 1976, Ap. J. (Letters), in press.Google Scholar
Lecar, M. 1976, private communication.Google Scholar
Lewin, W. G. 1976, MNRAS, in press.Google Scholar
Lewin, W. H. G., Doty, G., Clark, G. W., Rappaport, S. A., Bradt, H. V. D. Doxsey, R., Hearn, D. R., Hoffman, J. A., Jernigan, J. G., Li, F. K., Mayer, W., McClintock, J., Primini, F., and Richardson, J. 1976a, Ap. J. (Letters), 207, L95.CrossRefGoogle Scholar
Lewin, W. H. G., Li, F. K., Hoffman, J. A., Doty, J., Buff, J., Clark, G. and Rappaport, S. 1976b, preprint.Google Scholar
Liller, W. 1976a, private communication.Google Scholar
Liller, W. 1976b, IAU Circ. No. 2929.Google Scholar
Liller, M., Liller, W. 1976, Ap. J. (Letters), 207, L109.Google Scholar
Markert, T. H., Backman, D. E., Canizares, C. R., Clark, G. W., and Levine, A. M. 1975, Nature, 257, 32.CrossRefGoogle Scholar
Newell, B., DaCosta, G. S., and Norris, J. 1976, Ap. J. (Letters), 208, L55.Google Scholar
Ostrlker, J., Spitzer, L., and Chevalier, R. 1972, Ap. J. (Letters), 176, L51.Google Scholar
Peterson, C. J., and King, I. R. 1975, A. J., 80, 427.Google Scholar
Pye, J. P., Elvis, M., and Eadie, G. R. 1976, IAU Circ. No. 2985.Google Scholar
Sagdeev, R. A. 1976, IAU Circ. No. 2959.Google Scholar
Sandage, A., Smith, L. L., and Norton, R. H. 1966, Ap. J., 144, 894.Google Scholar
Seward, F. D., Page, C. G., Turner, M. J. L., and Pounds, K. A. 1976, MNRAS, 175, 39P.CrossRefGoogle Scholar
Seward, F. D., Burginyon, G. A., Grader, R. J., Hill, R. W., and Palmieri, T. M., 1972, Ap. J., 178, 131.CrossRefGoogle Scholar
Silk, J., and Aarons, J. 1975, Ap. J. (Letters), 200, L131.CrossRefGoogle Scholar
Trimble, V. 1976, preprint.Google Scholar
Ulmer, M. P., Murray, S. S., Gursky, H., and Bahcall, J. N. 1976, Ap. J., 208, 47.Google Scholar