Conclusion

Correlation between the Galactic loops and neu­tral hydrogen has been shown to exist. Of the theories for the origin of the loops mentioned in Section 1, the supernova remnant hypothesis seems most con­sistent with the geometry of the loops. However, on the presently available data it is not possible to decide whether it is more probable that these features re­present the remnants of normal supernova or of super-supemovae. Problems still remaining to be explained are the high degree of circularity of the loops, even where they seem to have crossed the Galactic plane, and the latitude variation of their intensity.

Acknowledgements. The authors wish to thank Professor J. H. Oort for valuable discussions in the course of this work. Professor Lovell is thanked for making available the facilities at Jodrell Bank.

Mr. J. van Kuilenburg generously made available un­published data of the neutral hydrogen distribution in the region of the North Polar Spur. Mrs. S. K. Pritchard assisted with the data reduction and preparation of the diagrams.

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Elly M. Berkhuijsen, C. G. T. Haslam Max-Planck-Institut fiir Radioastronomie BRD-5300 Bonn, ArgelanderstraBe 3 Germany

C. J. Salter

Laboratorio Nationale di Radioastronomia Istituto di Fisica Bologna, Italy

4 A Runaway Star Associated with Loop I?

5If the loops are indeed remnants of supemovae

6one might expect to find some present day mani­festation of the outbursts.

© European Southern Observatory • Provided by the NASA Astrophysics Data System