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An outline of the spiral structure of the Southern Milky Way

Published online by Cambridge University Press:  14 August 2015

B. J. Bok*
Affiliation:
Mount Stromlo Observatory

Extract

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It has become clear in recent years that the spiral features of our Galaxy — like those of all galaxies — are of recent origin and are presumably short-lived phenomena. To trace them optically, we need to confine ourselves to concentrations in the interstellar gas and to stars and star groupings recently formed from these. We are hence limited primarily to OB associations and star clusters in which the earliest spectral types for the stars are not later than B2, preferably O5 to B1. It is most important that radial velocities be measured for a fair sampling of these stars, especially so for directions in which the radial velocity effects due to galactic rotation vary appreciably with distance. Radial velocities of the stars in question and those found from interstellar absorption lines are not only useful as indicators of distance, but they are very much needed for the identification of star groups and their associated HI clouds, found by 21-cm techniques. They assist also in the study of HII regions, which can now be located by either radio or optical methods.

Type
Section 1: The Galaxy
Copyright
Copyright © Australian Academy of Science 1964 

References

Bok, B. J. (1956).—“Vistas in Astronomy.” (Ed. Beer, A..) vol. 2. pp. 1522–38. (Pergamon Press: London.)Google Scholar
Bok, B. J. (1959).— Observatory 79: 5862 =Mount Stromlo Obs. Reprint No. 16.Google Scholar
Bok, B. J., and van Wijk, U. (1952).— A.J. 57: 213–22.CrossRefGoogle Scholar
Davis, R. J. (1959).—, . p. 127.Google Scholar
Faulkner, D. J. (1963).— P.A.S.P. 75 (in press).CrossRefGoogle Scholar
Feast, M. W. (1958).— M.N. 118: 618–30.Google Scholar
Hoffleit, D. (1956).— Ap. J. 124: 6180.CrossRefGoogle Scholar
Kerr, F. J. (1962).— M.N. 123: 327–45.Google Scholar
Koelbloed, D. (1959).— B.A.N. 14: 265–78.Google Scholar
Mathewson, D. S., Healey, J. R., and Rome, J. M. (1962).— Aust. J. Phys. 15: 354–77.Google Scholar
Mills, B. Y. (1959).— P.A.S.P. 71: 267–91; “Paris Symposium on Radio Astronomy.” (Ed. Bracewell, R. N..) Symp. IAU 9: 431–46. [Paris 1958.] (Stanford Univ. Press.) CrossRefGoogle Scholar
Münch, L. (1954).—Bol. Tonantzintla No. 9: 2940.Google Scholar
Oort, J. H., Kerr, F. J., and Westerhout, G. (1958).— M.N. 118: 379–89.Google Scholar
Rodgers, A. W., Campbell, C. T., and Whiteoak, J. B. (1960).— M.N. 121: 103–10 = Mount Stromlo Obs. Reprint No. 31.Google Scholar
Schmidt, K. H. (1958).— A.N. 284: 76–8.Google Scholar
Sher, D. (1962).— Observatory 82: 63–6.Google Scholar
Smith, E. van P. (1956).— Ap. J. 124: 4360 = Harvard Obs. Reprint No. 439.CrossRefGoogle Scholar
Thackeray, A. D. (1956).— Nature 178: 1458.CrossRefGoogle Scholar
Thackeray, A. D., Wesselink, A. J., and Harding, G. A. (1962).— M.N. 124: 445–58.Google Scholar
Whiteoak, J. B. (1961).— M.N. 123: 245–56 =Mount Stromlo Obs. Reprint No. 49.Google Scholar