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A progress report on the Carina spiral feature

Published online by Cambridge University Press:  14 August 2015

B. J. Bok ,
A. A. Hine  and
E. W. Miller
B. J. Bok
Affiliation:
Steward Observatory, Tucson, Ariz., U.S.A.
A. A. Hine
Affiliation:
Steward Observatory, Tucson, Ariz., U.S.A.
E. W. Miller
Affiliation:
Steward Observatory, Tucson, Ariz., U.S.A.

Abstract

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The existing data on the distribution of O and B stars, of optical and radio H II sources, of H I and of cosmic dust have been assembled for the Carina-Centaurus Section of the Milky Way, lII = 265° to 305°. The published data have been supplemented by recent photoelectric UBV data and new photographic material. Two Working Diagrams (Figures 9 and 10) of the Carina Spiral Feature have been prepared. The Feature is sharply bounded at lII = 282° and again at lII = 295° in the range of distance from 1.5 to 6 kpc from the sun. Its outer rim is observed from the sun almost tangentially to a distance of 8 kpc from the sun. The Feature is found to bend at distances greater than 9 to 10 kpc from the sun, a result shown by both radio H I and radio H II data.

Figure 9 presents our basic data for the stellar, gas and dust components of the Feature. The O and early B stars and the H II Regions are closely associated and within 6 kpc of the sun they are concentrated in the range 285° < lII < 295°. The distribution in longitude of H I is broader and spills over on both sides of the O and B and the H II peak distributions. Long period cepheids yield a concentration similar to that shown by O and B stars and H II Regions. The visual interstellar absorption between lII = 282° and 295° is represented by a value AV = 0.5 mag kpc−1, or less, applicable to distances of 4 to 5 kpc. Much higher absorption is present on the outside of the Carina Spiral Feature, 265° < lII < 280°, where total visual absorptions as great as 3.5 mags. are found at distances of the order of 2 kpc. Even heavier absorption is indicated for these longitudes at 4 kpc from the sun, thus suggesting that the heavy obscuration on the outside of the Carina Spiral Feature is a phenomenon of general structural relevance (see Figures 8 and 9). Only small values of AV are found at the inside of the Spiral Feature.

The Working Diagram (Figure 10) shows that the O and B star peak and the H II peak have a width of 800 parsecs (12°) at 4 kpc from the sun, whereas the H I width is at least 1500 parsecs at the same distance. The peak of the O and B star distribution and of the H II distribution lies at about 600 parsecs (8° at 4 kpc) within the outer edge of the spiral feature. The heaviest interstellar absorption is on the outside of the Feature.

Type
Part II/Observations of Spiral Structure in Our Galaxy
Information
Symposium - International Astronomical Union , Volume 38: The Spiral Structure of our Galaxy , 1970 , pp. 246 - 261
Copyright
Copyright © Reidel 1970 

References

Baade, W. and Mayall, N. U.: 1951, Problems of Cosmical Aerodynamics Central Air Documents Office, Dayton, Ohio, p. 165.Google Scholar
Becker, W.: 1956, Vistas in Astronomy 2, 1515.CrossRefGoogle Scholar
Becker, W.: 1963, Z. Astrophys. 57, 117.Google Scholar
Becker, W.: 1964, Z. Astrophys. 58, 202.Google Scholar
Becker, W. and Fenkart, R.: 1963, Z. Astrophys. 56, 257.Google Scholar
Beer, A.: 1961, Monthly Notices Roy. Astron. Soc. 121, 191.CrossRefGoogle Scholar
Bok, B. J.: 1932, Harvard Repr. No. 77.Google Scholar
Bok, B. J.: 1956, Vistas in Astronomy 2, 1522.Google Scholar
Bok, B. J.: 1959, Observatory 79, 58.Google Scholar
Bok, B. J.: 1966, IAU Symposium No. 24, p. 228.Google Scholar
Bok, B. J. and Bok, P.F.: 1960, Monthly Notices Roy. Astron. Soc. 121, 531.Google Scholar
Bok, B. J. and Bok, P.F.: 1969, Astron. J. 74, 1125.CrossRefGoogle Scholar
Bok, B. J. and van Wijk, U.: 1952, Astron. J. 57, 213.CrossRefGoogle Scholar
Courtès, G.: 1969, private communication.Google Scholar
Courtès, G., Georgelin, Y. P. and Monnet, Y. M. G., and Pourcelot, A.: 1968, in Interstellar Ionized Hydrogen (ed. by Terzian, Y.), Benjamin, New York, p. 571.Google Scholar
Cousins, A. W. J. and Stoy, R. H.: 1963, Roy. Obs. Bull., No. 64.Google Scholar
Ewen, H. I. and Purcell, E. M.: 1951, Nature 168, 356.Google Scholar
Feast, M. W., Stoy, R. H., Thackeray, A. D., and Wesselink, A. J.: 1961, Monthly Notices Roy. Astron. Soc. 122, 239.Google Scholar
Feast, M. W. and Shuttleworth, M.: 1965, Monthly Notices Roy. Astron. Soc. 130, 245, and corrigenda 134, 107.Google Scholar
Feinstein, A.: 1969, Monthly Notices Roy. Astron. Soc. 143, 273.Google Scholar
Fernie, J. D.: 1968, Astron. J. 73, 995.CrossRefGoogle Scholar
Graham, J. A.: 1970, IAU Symposium No. 38, p. 262.Google Scholar
Graham, J. A. and Lyngå, G.: 1965, Mem. Mt Stromlo Obs., No. 18.Google Scholar
Hill, E. R.: 1968, Australian J. Phys. 21, 735.Google Scholar
Hindman, J. V.: 1969, in preparation.Google Scholar
Hoffleit, D.: 1953, Harvard Ann. 119, 37.Google Scholar
Kerr, F. J.: 1969a, Ann. Rev. Astron. Astrophys. 7, 39.Google Scholar
Kerr, F. J.: 1969b, Austr. J. Phys. Astrophys. Suppl. 9, 1.Google Scholar
Kerr, F. J. and Hindman, J. V.: 1969, in preparation.Google Scholar
Klare, G. and Szeidl, B.: 1966, Veröff. Landessternwarte Heidelberg-Königstuhl 18, 9.Google Scholar
Kraft, R. R.: 1965, Stars and Stellar Systems 5, 157.Google Scholar
Lindoff, U.: 1968, Ark. Astron. 5, 1.Google Scholar
Lodèn, L. O.: 1968, Ark. Astron. 5, 161.Google Scholar
Lyngå, G.: 1964, Medd. Lund Obs., Series II, No. 39.Google Scholar
Lyngå, G.: 1968a, Ark. Astron. 5, 161.Google Scholar
Lyngå, G.: 1968b, Proc. Astron. Soc. Austr. 1, 92.CrossRefGoogle Scholar
Mathewson, D. S., Healey, J. R., and Rome, J. M.: 1962, Austr. J. Phys. 15, 354.Google Scholar
Morgan, W. W., Sharpless, S., and Osterbrock, D. E.: 1952, Astron. J. 57, 3.Google Scholar
Neckel, T.: 1967, Veröff. Landessternwarte Heidelberg-Königstuhl 19.Google Scholar
Olmsted, M.: 1966, Astron. J. 71, 916.CrossRefGoogle Scholar
Oort, J. H., Kerr, F. J., and Westerhout, G.: 1958, Monthly Notices Roy. Astron. Soc. 118, 379.Google Scholar
Rodgers, A. W., Campbell, C. T., and Whiteoak, J. B.: 1960a, Monthly Notices Roy. Astron. Soc. 121, 103.CrossRefGoogle Scholar
Rodgers, A. W., Campbell, C. T., Whiteoak, J. B., Bailey, H. H., and Hunt, V. O.: 1960b, An Atlas of H-Alpha Emission in the Southern Milky Way, Mt Stromlo Obs., Australian National Univ., Canberra.Google Scholar
Schmidt, M.: 1965, Stars and Stellar Systems 5, 513.Google Scholar
Schmidt-Kaler, T.: 1964, Z. Astrophys. 58, 217.Google Scholar
Schmidt-Kaler, T.: 1965, Landolt-Börnstein, New Series 1, 284.Google Scholar
Sher, D.: 1965, Quart. J. Roy. Astron. Soc. 6, 299.Google Scholar
Smith, L. F.: 1966, Ph.D. Thesis, Australian National University.Google Scholar
Velghe, A. G.: 1969, unpublished.Google Scholar
Westerhout, G.: 1968, Maryland-Green Bank Galactic 21 cm Line Survey, 2nd ed., Univ. of Maryland.Google Scholar
Westerlund, B. E.: 1960, Ark. Astron. 2, 419.Google Scholar
Wilson, T. L.: 1969, Ph.D. Thesis, M.I.T. Google Scholar