Abstract
It is shown in the present paper that properties of the spiral wave in the Galaxy are determined by the mass distribution of its flat subsystem rather than by the full mass distribution. Then it turns out that better agreement with the observed spiral pattern furnish the ‘long’ waves in contrast to the ‘short’ waves in the Linet al. (1969) theory. With the surface density σI=40M ⊙ /ps 2 which is taken in the first approximation as independent on the galacto-centric distance, and the pattern velocityΩ p=23 km/s kps, the evaluated spiral pattern fits surprisingly well with the Weaver (1970) map of the HI-distribution in the Galaxy, and is in good agreement with the Kerr (1969) map. The inner Lindblad resonance occurs at 2 kps from the Galaxy center, where Weaver has placed the ring condensation of the gas, and the outer resonance lies close by 14 kps. At the outer resonance the nonlinear phenomena are expected, which lead to chaotization of the regular structure. This seems to be consistent with the Weaver (1970) and Kerr (1969) maps.
The hypothesis is suggested which associates the generating mechanism of spiral waves with the rotating bar of old stars in the center of the Galaxy. Depending on the velocity of the bar rotation and the bar length, different combinations of the normal wave pattern and bar-like structure may occur, which possibly explains the great variety of transition forms between normal and barred spirals. In the proposed theory the packet of spiral waves moves from the inner Lindblad resonance outwards and could be permanently maintained by the ‘generator’ in the center of the Galaxy. Therefore, the difficulty associated with the rapid obliteration of the packet (Toomre, 1969) does not arise.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Baade, W.: 1944,Astrophys. J. 100, 137; 1944, Mt. Wilson Contr., No. 696.
Contopoulos, G.: 1970,Astrophys. J. 160, 113.
Contopoulos, G.: 1971,Astrophys. J. 163, 181.
Courtès, G., Georgelin, Y. M., and Monnet, G.: 1970, in W. Becker and G. Contopoulos (eds.),IAU Symp. 38, 209; D. Reidel Publ. Comp., Dordrecht-Holland.
Goldreich, P. and Lynden-Bell, D.: 1965,Monthly Notices Roy. Astron. Soc. 130, 97.
Kalnajs, A. J.: 1970, in W. Becker and G. Contopoulos (eds.),IAU Symp. 38, 318; D. Reidel Publ. Comp., Dordrecht-Holland.
Kerr, F. J.: 1969,Ann. Rev. Astron. Astrophys. 7, 39.
Lin, C. C.: 1970,Ann. Rev. Astron. Astrophys. 7, 377.
Lin, C. C. and Shu, F.: 1964,Astrophys. J. 140, 646.
Lin, C. C. and Shu, F.: 1966,Proc. Nat. Acad. Sci. U.S.A. 55, 229.
Lin, C. C., Yuan, C., and Shu, F.: 1969,Astrophys. J. 155, 721.
Mark, J.: 1971,Proc. Nat. Acad. Sci. U.S.A. 68, 2095.
Marochnik, L. S. and Suchkov, A. A.: 1969a,Astrophys. Space Sci. 4, 317.
Marochnik, L. S. and Suchkov, A. A.: 1969b,Soviet Astron. 23, 252, 411.
Marochnik, L. S. and Suchkov, A. A.: 1972,Soviet Physics Uspekhi, in press.
Schmidt, M.: 1965, in A. B. Blaauw and M. Schmidt (eds.),Galactic Structure, Univ. of Chicago Press, Chicago, p. 513.
Shu, F.: 1970a,Astrophys. J. 166, 89.
Shu, F.: 1970b,Astrophys. J. 166, 99.
Shu, F., Stachnik, R. V., and Yost, J. C.: 1971,Astrophys. J. 166, 465.
Simonson, S. C.: 1970,Astron. Astrophys. 9, 163.
Strömgren, P.: 1967,IAU Symp. 31, 323.
Toomre, A.: 1969,Astrophys. J. 158, 899.
Vaucouleurs, G. de: 1959, inHandbuch der Physik, B. LIII, Astrophysik IV, Springer-Verlag.
Weaver, H.: 1970, in W. Becker and G. Contopoulos (eds.),IAU Symp. 38, 126; D. Reidel Publ. Comp., Dordrecht-Holland.
Wielen, R.: 1971,Mitt. Astron. Ges., Nr. 30, p. 31, Hamburg.
Yuan, C.: 1969,Astrophys. J. 158, 899.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Marochnik, L.S., Mishurov, Y.N. & Suchkov, A.A. On the spiral structure of our Galaxy. Astrophys Space Sci 19, 285–292 (1972). https://doi.org/10.1007/BF00645713
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00645713