Hostname: page-component-77c89778f8-sh8wx Total loading time: 0 Render date: 2024-07-17T23:21:57.075Z Has data issue: false hasContentIssue false

42. Solar cosmic radiation and the interstellar magnetic field

Published online by Cambridge University Press:  18 July 2016

A. Ehmert*
Affiliation:
Max Planck Institute for the Physics of the Stratosphere, Weissenau, Germany

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The increase of cosmic radiation on 23 February 1956 by solar radiation exhibited in the first minutes a high peak at European stations that were lying in direct impact zones for particles coming from a narrow angle near the sun, whilst other stations received no radiation for a further time of 10 minutes and more. An hour later all stations in intermediate and high latitudes recorded solar radiation in a distribution as would be expected if this radiation fell into the geomagnetic field in a fairly isotropic distribution. The intensity of the solar component decreased at this time at all stations according to the same hyperbolic law (~t–2).

It is shown, that this decreasing law, as well as the increase of the impact zones on the earth, can be understood as the consequence of an interstellar magnetic field in which the particles were running and bent after their ejection from the sun.

Considering the bending in the earth's magnetic field, one can estimate the direction of this field from the times of the very beginning of the increase in Japan and at high latitudes. The lines of magnetic force come to the earth from a point with astronomical co-ordinates near 12·00, 30° N. This implies that within the low accuracy they have the direction of the galactic spiral arm in which we live. The field strength comes out to be about 0·7 × 10–6 gauss. There is a close agreement with the field, that Fermi and Chandrasekhar have derived from Hiltner's measurements of the polarization of starlight and the strength of which they had estimated to the same order of magnitude.

Type
Part V: Electromagnetic State in Interplanetary Space
Copyright
Copyright © Cambridge University Press 1958 

References

1. Sandström, A. E. Tellus , 8, 279, 1956.CrossRefGoogle Scholar
2. Brode, R. B. and Goodwin, A. Jr. Phys. Rev. 103, 377, 1956.CrossRefGoogle Scholar
3. Meyer, P., Parker, E. N. and Simpson, J. A. * Phys. Rev. 104, 768, 1956. Cosmic radiation studies, Enrico Fermi Institute for Nuclear Studies (Chicago, 1956).CrossRefGoogle Scholar
4. Rose, C. D. and Katzmann, J. * (in the press).Google Scholar
5. Marsden, P. L., Berry, J. W., Fieldhouse, P. and Wilson, J. G. * (in the press).Google Scholar
6. Meyer, B. Z. Naturf. 11a, 326, 1956.CrossRefGoogle Scholar
7. Ehmert, A. and Pfotzer, G. Z. Naturf. 11a, 322, 1956.CrossRefGoogle Scholar
8. Brown, R. J. Atmos. Terr. Phys. 8, 278, 1956.Google Scholar
9. Sekido, Y., Ishii, C. * and Migazaki, Y. * (in the press).Google Scholar
10. Sittkus, A., Kühn, W. and Andrich, E. * Z. Naturf. 11a, 325, 1956.CrossRefGoogle Scholar
11. Forbush, S. E. * (in the press).Google Scholar
12. Vernov, S. N., Kopilov, Yu. M., Dorman, L. I. and Shafer, Yu. G. * (in the press).Google Scholar
13. Forbush, S. E. Phys. Rev. 70, 771–2, 1946.CrossRefGoogle Scholar
14. Firor, I. Phys. Rev. 94, 1017, 1954.CrossRefGoogle Scholar
15. Chandrasekhar, S. and Fermi, E. Astrophys. J. 118, 113 and 116, 1953.CrossRefGoogle Scholar
16. Hiltner, W. A. Astrophys. J. 109, 471, 1949; 114, 241, 1951.CrossRefGoogle Scholar
17. Pfotzer, G. Mitteilungen aus dem Max-Planck-Institut für Physik der Stratosphäre , no. 7, 1956.Google Scholar
18. Alfvén, H. Tellus , 6, 232, 1954.CrossRefGoogle Scholar
19. Ehmert, A. Z. Naturf. 3a, 264–85, 1948.Google Scholar
20. Meyer, P., Parker, E. N. and Simpson, J. A. ‘The solar cosmic rays of February 1956 and their propagation through interplanetary space’, Cosmic radiation studies , Enrico Fermi Institute for Nuclear Studies, Chicago, 1956.Google Scholar
21. Winckler, J. R. Phys. Rev. 104, 220, 1956.CrossRefGoogle Scholar
22. Sandström, A. E. Collection by Elliot and Gold.Google Scholar
23. Trefall, H. and Trumpy, B. Collection by Elliot and Gold.Google Scholar
24. Brunberg, E. Å. This symposium, Paper 40.Google Scholar