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.

0957 + 561 A, B: twin quasistellar objects or gravitational lens?

Nature volume 279, pages 381–384 (1979)Cite this article

0957 + 561 A, B are two QSOs of mag 17 with 5.7 arc s separation at redshift 1.405. Their spectra leave little doubt that they are associated. Difficulties arise in describing them as two distinct objects and the possibility that they are two images of the same object formed by a gravitational lens is discussed.

SPECTROSCOPIC observations have been in progress for several years on QSO candidates using a survey of radio sources made at 966 MHz with the MkIA telescope at Jodrell Bank. Many of the identifications have been published by Cohen et al.1 with interferometric positions accurate to -2 arc s and a further list has been prepared by Porcas et al2. The latter list consists of sources that were either too extended or too confused for accurate interferometric positions to be measured, and these were observed with the pencil-beam of the 300 ft telescope at NRAO, Green Bank at ? 6 cm and All cm. This gave positions with typical accuracy 5-10 arc s and the identifications are estimated as 80% reliable.

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

Learn more

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

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  1. Cohen, A. M., Porcas, R. W., Browne, I. W. A., Daintree, E. J. & Walsh, D. Mem. R. astr. Soc. 84, 1 (1977).

    ADS  Google Scholar 

  2. Porcas, R. W. et al. Mon. Not. R. astr. Soc. (submitted).

  3. Stockton, A. N. Astrophys. J. 223, 747 (1978).

    Article  ADS  Google Scholar 

  4. Weymann, R. J., Williams, R. E., Peterson, B. M. & Turnshek, D. A. Astrophys. J. (submitted).

  5. Wolfe, A. M., Broderick, J. J., Condon, J. J. & Johnston, K. J. Astrophys. J. Lett. 208, L47 (1976).

    Article  ADS  CAS  Google Scholar 

  6. Sanitt, N. Nature 234, 199 (1971).

    Article  ADS  Google Scholar 

  7. Schechter, P. Astrophys. J. 203, 297 (1976).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. ∗University of Manchester, Nuffield Radio Astronomy Laboratories, Jodrell Bank, Macclesfield, Cheshire, UK https://www.nature.com/nature

    D. Walsh∗

  2. †Institute of Astronomy, Cambridge, UK https://www.nature.com/nature

    R. F. Carswell†

  3. ‡Steward Observatory, University of Arizona, Tucson, Arizona 85721 https://www.nature.com/nature

    R. J. Weymann‡

Authors
  1. D. Walsh∗
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. R. F. Carswell†
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. R. J. Weymann‡
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Walsh∗, D., Carswell†, R. & Weymann‡, R. 0957 + 561 A, B: twin quasistellar objects or gravitational lens?. Nature 279, 381–384 (1979). https://doi.org/10.1038/279381a0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/279381a0

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

Advanced 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