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The Radio Properties of SNRs in the Magellanic Clouds

Published online by Cambridge University Press:  04 August 2017

B. Y. Mills*
Affiliation:
University of Sydney, NSW 2006 Australia

Extract

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An understanding of the radio properties and evolution of Galactic supernova remnants has always been hampered by the difficulty of measuring distances. A conventional wisdom has developed around a set of ‘good’ calibrators but most workers involved have drawn attention to the uncertainties and the possibility of selection effects distorting results. This major difficulty is completely overcome by studying SNRs in the Magellanic Clouds. Although there is uncertainty in the absolute distance scale, relative distances can be determined to better than 10% and differences of this magnitude are not significant when intercomparing SNRs. There is, however, another set of problems associated with sensitivity and resolution. The Clouds are an order of magnitude more distant than the average distance of Galactic SNRs, thus many of the SNRs are close to or below the sensitivity limits of most of the southern radiotelescopes and, until recently, the resolution available has often been inadequate to separate non-thermal sources from thermal HII regions, so that both flux densities and spectra have been subject to error. Also there are ∼ 1000 extragalactic background sources which can mimic the flux density and spectra of SNRs in the Clouds, particularly when close to or behind HII regions; as a result numerous incorrect or doubtful SNR identifications have been suggested.

Type
VI. Supernova Remnants in Other Galaxies
Copyright
Copyright © Reidel 1983 

References

Clark, D.H. & Caswell, J.L.: 1976, M.N.R.A.S., 174, 267.Google Scholar
Clark, D.H. & Stephenson, F.R.: 1977, “The Historical Supernovae”, (Pergamon), p. 207.Google Scholar
Clarke, J.N.: 1976, M.N.R.A.S., 174, 393.Google Scholar
Clarke, J.N., Little, A.G. and Mills, B.Y.: 1976, Aust. J. Phys. Astrophys. Suppl., No. 40, 1.Google Scholar
Long, K.S., Helfand, D.J. and Grebalsky, D.A.: 1981, Astrophys. J., 248, 925.Google Scholar
Mathewson, D.S. and Healey, J.R.: 1964, “The Galaxy and the Magellanic Clouds”, (eds) Kerr, F.J. and Rodgers, A.W. (Canberra; Australian Academy of Science), p. 283.Google Scholar
Mathewson, D.S. and Clarke, J.N.: 1972, Astrophys. J. Lett., 178, L105.Google Scholar
Mathewson, D.S. and Clarke, J.N.: 1973a, Astrophys. J., 179, 89.Google Scholar
Mathewson, D.S. and Clarke, J.N.: 1973b, Astrophys. J., 180, 725.Google Scholar
Mathewson, D.S. and Clarke, J.N.: 1973c, Astrophys. J., 182, 697.Google Scholar
Mathewson, D.S., Ford, V.L., Dopita, M.A., Tuohy, I.R., Long, K.S. and Helfand, D.J.: Astrophys. J. (in press).Google Scholar
McGee, R.X., Brooks, J.W. and Batchelor, R.A.: 1972, Aust. J. Phys., 25, 581.Google Scholar
McGee, R.X., Newton, L.M. and Brooks, J.W.: 1974, Aust. J. Phys., 27, 79.CrossRefGoogle Scholar
McGee, R.X., Newton, L.M. and Butler, P.W.: 1978, M.N.R.A.S., 183, 799.Google Scholar
Meaburn, J.: 1980, M.N.R.A.S., 192, 365.Google Scholar
Mills, B.Y.: 1981, Proc. astr. Soc. Aust., 4, 156.CrossRefGoogle Scholar
Mills, B.Y., Little, A.G., Durdin, J.M. and Kesteven, M.J.L.: 1982, M.N.R.A.S., 200, 1007.Google Scholar
Mills, B.Y., Turtle, A.J., Little, A.G. and Durdin, J.M., (in preparation).Google Scholar
Milne, D.K., Caswell, J.L. and Haynes, R.F.: 1980, M.N.R.A.S., 191, 469.Google Scholar
Seward, F.D. and Mitchell, M.: 1981, Astrophys. J., 243, 736.Google Scholar
Turtle, A.J. and Mills, B.Y.: 1979, N.Z.J. Sci., 22, 543.Google Scholar
Westerlund, B.E. and Mathewson, D.S.: 1966, M.N.R.A.S., 131, 371.Google Scholar