Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Spectral characteristics of transient X-ray sources

Abstract

THE transient X-ray sources A1524—62 and A0535+26 were briefly observed by the University College, London, proportional counter spectrometer, experiment C on the Ariel V satellite (P. W. Sanford and J. C. Ives, unpublished). The resulting spectra help to complete the spectral history of these two sources, making seven sources for which there is now extensive spectral information. A general scheme emerges from these in which the sources with hard spectra (n 2) show little spectral evolution and those with soft spectra (n >2) exhibit marked softening with time. We discuss here this subdivision in relation to other properties of the sources.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Pounds, K. A., IAU Circ., No. 2729 (1974).

  2. Kaluzienski, L. J., et al. Astrophys. J. Lett., 201, L121 (1975).

    Article  ADS  Google Scholar 

  3. Brown, R. L., and Gould, J., Phys. Rev. D., 1, 2252 (1970).

    Article  ADS  Google Scholar 

  4. Coe, M. J., Carpenter, G. F., Engle, A. R., and Quenby, J. J., Nature, 256, 630 (1975).

    Article  ADS  Google Scholar 

  5. Ricker, G. R., et al. Astrophys. J. Lett., 204, L73 (1976).

    Article  ADS  Google Scholar 

  6. Ricketts, M. J., Turner, M. J. L., Page, C. G., and Pounds, K. A., Nature, 256, 631 (1975).

    Article  ADS  Google Scholar 

  7. Evans, W. D., Belian, R. D., and Connor, J. P., Astrophys. J. Lett., 159, L57 (1970).

    Article  ADS  Google Scholar 

  8. Evans, W. D., Belian, R. D., and Connor, J. P., Proc. Conf. Transient osmic and X-ray Sources, Los Alamos, New Mexico (1973).

    Google Scholar 

  9. Belian, R. D., Connor, J. P., and Evans, W. D., Proc. Conf. Transient osmic and X-ray Sources, Los Alamos, New Mexico (1973).

    Google Scholar 

  10. Matilsky, T., Giacconi, R., Gursky, H., Kellogg, E., and Tananbaum, H., Astrophys. J. Lett., 174, L53 (1972).

    Article  ADS  Google Scholar 

  11. Chevalier, C., and Ilovaisky, S. A., IAU Circ., No. 2778 (1975).

  12. Eyles, C. J., Skinner, G. K., Willmore, A. P., and Rosenberg, F. D., Nature 254, 577 (1975).

    Article  ADS  Google Scholar 

  13. Ives, J. C., Sanford, P. W., and Bell-Burnell, S. J., Nature, 254, 578 (1975).

    Article  ADS  Google Scholar 

  14. Eyles, C. J., Skinner, G. K., Willmore, A. P., and Rosenberg, F. D., Nature, 257, 291 (1975).

    Article  ADS  CAS  Google Scholar 

  15. Branduardi, G., Ives, J. C., Sanford, P. W., and Maraschi, L., Mon. Not. R. astr. Soc., 175, 47 (1976).

    Article  ADS  Google Scholar 

  16. Liller, W., IAU Circ., No. 2780 (1975).

  17. Rosenberg, F. D., Eyles, C. J., Skinner, G. K., and Willmore, A. P., Nature, 256, 628 (1975).

    Article  ADS  Google Scholar 

  18. Elvis, M., Page, C. G., Pounds, K. S., Ricketts, M. J., and Turner, M. J. L., Nature, 257, 656 (1975).

    Article  ADS  CAS  Google Scholar 

  19. Ricketts, M. J., Pounds, K. A., and Turner, M. J. L., Nature, 257, 657 (1975).

    Article  ADS  CAS  Google Scholar 

  20. Kellogg, E., Gursky, H., Murray, S., Tananbaum, H., and Giacconi, R., Astrophys J. Lett., 169, L99 (1971).

    Article  ADS  Google Scholar 

  21. Clark, G. W., Lectures at the Enrico Fermi Summer School on Physics and strophysics of Neutron Stars and Black Holes, (Varenna, Italy, 1975).

    Google Scholar 

  22. Fabian, A. D., Mon. Not. R. astr. Soc., 173, 161 (1975).

    Article  ADS  Google Scholar 

  23. Pacini, F., and Shapiro, S. L., Nature, 255, 618 (1975).

    Article  ADS  Google Scholar 

  24. Forman, W., and Liller, W., Astrophys. J. Lett., 183, LI 17 (1973).

    Article  Google Scholar 

  25. Ward, M. J., Pension, M. V., Murray, C. A., and Clements, E. D., Nature, 257, 659 (1975).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

MARASCHI, L., HUCKLE, H., IVES, J. et al. Spectral characteristics of transient X-ray sources. Nature 263, 34–36 (1976). https://doi.org/10.1038/263034a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/263034a0

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing