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Dynamical Effects in the Central Region of the Galaxy

Published online by Cambridge University Press:  12 April 2016

Robert H. Sanders
Robert H. Sanders*
Affiliation:
Kapteyn Astronomical Laboratory, Groningen, The Netherlands

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For the purpose of this Paper, I will define the central region of the galaxy as being the inner four kiloparsecs. I make this definition for three reasons:

1) Outside of four kiloparsecs, the rotation curve for the galaxy is well-defined by the Schmidt disk model; whereas, inside four kiloparsecs, the effects of a central spherical component on the rotation curve become conspicuous. This inner spheroid is a dynamical component of the galaxy which is distinct from the disk and may be distinct from the extended halo component as well.

2) There is a conspicuous hole in the total gas density distribution inside 4 kpc.

3) High peculiar or non-circular gas velocities are observed within the inner 4 kpc; velocities ranging from the 53 km s-1 of the so-called 3 kpc arm, to 165 km s-1 in the molecular clouds within 300 pc of the center.

I will now discuss these points in some greater detail.

Type
Part II: Evolution of the Central Parts of the Galaxy
Information
International Astronomical Union Colloquium , Volume 45: Chemical and Dynamical Evolution of our Galaxy , September 1977 , pp. 103 - 113
Copyright
Copyright © Geneva Observatory 1977

References

Balick, B., Brown, R.L. 1974, Ap. J., 194, 265 Google Scholar
Balick, B., Sanders, R.H. 1974, Ap. J., 192, 325 Google Scholar
Bania, T.M. 1977, Ap. J., 216, 381 Google Scholar
Becklin, E.E., Neugebauer, G. 1968, Ap. J., 151, 145 CrossRefGoogle Scholar
Becklin, E.E., Neugebauer, G. 1975, Ap. J., 200, L71 Google Scholar
Ekers, R.D., Goss, W.M., Schwarz, U.J., Downs, D., Rogstad, D.H. 1975, Astron. Astrophys., 43, 159 Google Scholar
Gordon, M.A., Burton, W.B. 1976, Ap. J., 208, 346 Google Scholar
Huntley, J.M. 1976, unpublished calculationsGoogle Scholar
Kaifu, J., Kato, T., Iguchi, T. 1972, Nature Phys. Sc., 238, 105 Google Scholar
Kellerman, K.I., Schaffer, D.B., Clark, B.G., Geldzahler, B.J. 1977, Ap. J., 214, L61 Google Scholar
Kerr, F.J. 1968, in Radio Astronomy and the Galactic System, IAU Symp. 31, Ed. van Woerden, H. Google Scholar
Kruit, P.C van der 1971, Astron. & Astrophys., 13, 405 Google Scholar
Lin, C.C. 1970, in IAU Symp. 38: The Spiral Structure of our Galaxy, eds. Becker and Contopolous Google Scholar
Lin, C.C, Shu, F.H. 1964, Ap. J., 140, 646 Google Scholar
Mark, J.W-K. 1974, Ap. J., 193, 539 CrossRefGoogle Scholar
Oort, J.H. 1971, Nuclei of Galaxies, ed. O’Connell, D.J.K. (Amsterdam: North Holland)Google Scholar
Oort, J.H. 1977, Ann. Rev. Astr. and Ap. 15 (in press)CrossRefGoogle Scholar
Pauls, T., Mezger, P.G., Churchwell, E. 1974, Astron. & Astrophys., 34, 327 Google Scholar
Rougoor, G.W., Oort, J.H. 1960, Proc. Natl. Acad. Sci. USA, 46, 1 Google Scholar
Rougoor, G.W. 1964, Bull. Astr. Inst. Netherlands, 17, 381 Google Scholar
Rubin, V.C., Ford, W.K. Jr. 1971, Ap. J., 170, 25 Google Scholar
Sanders, R.H., Lowinger, T. 1972, Astron. J., 77, 292 Google Scholar
Sanders, R.H., Prendergast, K.H., 1974, Ap. J., 188, 439 Google Scholar
Scoville, N.Z. 1972, Ap. J., 175, L127 Google Scholar
Spitzer, L. 1968, Diffuse Matter in Space (New York: Interscience)Google Scholar
Toomre, A. 1963, Ap. J., 138, 385 Google Scholar
Wollman, E.R., Gaballe, T.R., Lacy, J.H., Towns, C.H., Rank, D.M. 1976, Ap. J., 205, 15 CrossRefGoogle Scholar