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Discovery of hard X-ray pulsations from the transient source GRO J1744 – 28

Abstract

AN UNUSUAL astronomical source of hard X-ray bursts, GRO J1744 – 28, was discovered recently1,2. The properties of this source differ markedly from those of other known high-energy burst sources—X-ray bursters, soft γ-ray repeaters and γ-ray bursters— suggesting that it may represent a new type of source. The bursts probably arise from unstable accretion of matter onto a compact object2, such as a neutron star, but the nature of the object and the origin of the burst instability have not been revealed by observations of the bursts themselves. Here we report the detection of coherent X-ray pulsations, with a period of 467 milliseconds, from GRO J1744 – 28; these are the first persistent pulsations seen in a bursting X-ray source. These pulses and their timing indicate that the object is a magnetized neutron star, accreting gas from a low-mass companion star. The pulsation rate has been increasing during the period of our observations, indicating that an accretion disk has been formed and that the transfer of matter from the disk is spinning up the neutron star. The source of the instability that leads to the bursts remains unknown.

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References

  1. Fishman, G. J. et al. IAU Circ. No. 6272 (1995).

  2. Kouveliotou, C. et al. Nature 379, 799–801 (1996).

    ADS  CAS  Article  Google Scholar 

  3. Fishman, G. J. et al. in Gamma Ray Observatory Science Workshop (ed. Johnson, W. N.) 39–50 (NASA, Goddard Space Flight Center, Greenbelt, MD, 1989).

    Google Scholar 

  4. White, N. E., Swank, J. M. & Holt, S. S. Astrophys. J. 270, 711–734 (1983).

    ADS  CAS  Article  Google Scholar 

  5. Ftaclas, C., Kearney, M. W. & Pechenick, K. Astrophys. J. 300, 203–208 (1986).

    ADS  CAS  Article  Google Scholar 

  6. Paczynski, B. Acta astr. 17, 287–296 (1967).

    ADS  Google Scholar 

  7. Phinney, E. S. & Kulkarni, S. R. A. Rev. Astr. Astrophys. 32, 591–639 (1994).

    ADS  Article  Google Scholar 

  8. Zahn, J. P. Astr. Astrophys. 57, 383–394 (1977).

    ADS  Google Scholar 

  9. Henrichs, H. F. in Accretion Driven Stellar X-ray Sources (eds Lewin, W. H. G. & van den Heuvel, E. P. J.) 393–429 (Cambridge Univ. Press, 1983).

    Google Scholar 

  10. Ghosh, P. & Lamb, F. Astrophys. J. 232, 259–276 (1979).

    ADS  Article  Google Scholar 

  11. Spruit, H. C. & Taam, R. E. Astrophys. J. 402, 593–604 (1993).

    ADS  Article  Google Scholar 

  12. Blondin, J. M. & Freese, K. Nature 323, 786–788 (1986).

    ADS  Article  Google Scholar 

  13. Taam, R. E. & van den Heuvel, E. P. J. Astrophys. J. 305, 235–235 (1986).

    ADS  CAS  Article  Google Scholar 

  14. Romani, R. W. Nature 347, 741–743 (1990).

    ADS  Article  Google Scholar 

  15. Lewin, W. H. G., Rutledge, R. E., Kommers, J. M., Van Paradijs, J. & Kouveliotou, C. Astrophys. J. Lett. (in the press).

  16. Milgrom, M. Astr. Astrophys. 172, L1–L2 (1987).

    ADS  CAS  Google Scholar 

  17. Hanawa, T., Hirotani, K. & Kawai, N. Astrophys. J. 336, 920–923 (1989).

    ADS  Article  Google Scholar 

  18. Walker, M. A. Astrophys. J. 385, 651–660 (1992).

    ADS  Article  Google Scholar 

  19. Hayakawa, S. Phys. Rep. 121, 317–406 (1985).

    ADS  CAS  Article  Google Scholar 

  20. Kuijpers, J. & Kuperus, M. Astr. Astrophys. 286, 491–496 (1994).

    ADS  Google Scholar 

  21. Hanami, H. Mon. Not. R. astr. Soc. 233, 423–436 (1988).

    ADS  Article  Google Scholar 

  22. Singh, L. M. & Duorah, H. L. Astrophys. Space Sci. 92, 143–148 (1983).

    ADS  Article  Google Scholar 

  23. Baan, W. A. Astrophys. J. 214, 245–250 (1977).

    ADS  CAS  Article  Google Scholar 

  24. Baan, W. A. Astrophys. J. 277, 987–994 (1979).

    ADS  Article  Google Scholar 

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Finger, M., Koh, D., Nelson, R. et al. Discovery of hard X-ray pulsations from the transient source GRO J1744 – 28. Nature 381, 291–293 (1996). https://doi.org/10.1038/381291a0

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