Red-Shift Absorption Spectrum of the Cygnus-A Radio Source

Article metrics


A MEASUREMENT to check the 21-cm. hydrogen line absorption spectrum of Cygnus-A (19N4A) reported by Lilley and McClain1 is important in view of the cosmological significance of their result. The absorption was observed by these authors within a 3 Mc./s. band centred on 1341 Mc./s. and was considered to be due to absorption in a neutral hydrogen cloud associated with the Cygnus-A source and receding with it at the optically determined2 velocity of 16,800 km./sec.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Lilley, A. E., and McClain, E. F., Astrophys. J., 123, 172 (1956).

  2. 2

    Baade, W., and Minkowski, R., Astrophys. J., 119, 206 (1954).

  3. 3

    Muller, C. A., Paris Symposium on Radio Astronomy, edit. Bracewell, R. N. (Stanford University Press, 1959).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

DAVIES, R., JENNISON, R. Red-Shift Absorption Spectrum of the Cygnus-A Radio Source. Nature 184, 803–804 (1959) doi:10.1038/184803b0

Download citation

Further reading


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.