Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-08T07:26:52.933Z Has data issue: false hasContentIssue false
  • English
  • Français

The mass and light distribution of the galaxy: a three-component model

Published online by Cambridge University Press:  14 August 2015

J. P. Ostriker  and
J. A. R. Caldwell
J. P. Ostriker
Affiliation:
Princeton University Observatory
J. A. R. Caldwell
Affiliation:
Princeton University Observatory

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The galaxy is represented schematically by a three-component model: a disc having the form of a modified exponential distribution, a spheroidal (bulge + nucleus) component and a dark halo component which, following the nomenclature of Einasto, we call the corona. The shapes of these components, chosen on the basis of observations of other galaxies, are consistent with imperfect knowledge of the Galaxy; values of the adjustable parameters are chosen by a least square minimization technique to best fit the most accurate kinematical and dynamical galactic observations. The local radius, circular velocity and escape velocity are found to be (R⊙, V⊙, Vesc) = (9.05 ± 0.33 kpc, 247 ± 13 km/s, 550 ± 24) quite close to the values determined from observations directly. The masses in the three components are (MD, MSp, MC) = (0.78 ± 0.13, 0.81 ± 0.09, 20.3) × 1011 M⊙ for a model with coronal radius of 335 kpc. If the quite uncertain coronal radius is reduced to 100 kpc the model is essentially unchanged except that then MC = 6.65 × 1011 M⊙. The disc and spheroidal components have in either case luminosities (in the visual band of (LD, LSp) = (2.0, 0.2) × 1010 L⊙. The galaxy is a normal giant spiral of type Sb-Sc similar to NGC 4565.

Type
VIII. THE SPHEROIDAL COMPONENT
Information
Symposium - International Astronomical Union , Volume 84: The Large-Scale Characteristics of the Galaxy , 1979 , pp. 441 - 450
Copyright
Copyright © Reidel 1979 

References

Burton, W.: 1971, Astron. Astrophys. 10, 76.Google Scholar
deVaucouleurs, G.: 1959, Handbuch der Physik, 53 (Springer-Verlag:Berlin).Google Scholar
Eggen, O. J.: 1964, Royal Obs. Bulletin No. 84.Google Scholar
Erikson, R.: 1975, Astrophys. J. 195, 343.Google Scholar
Einasto, J.: 1970, Teated Tartu Obs. 26, 1.Google Scholar
Fall, M. and Rees, M.: 1978, preprint.Google Scholar
Fatchikhin, N.: 1970, Soviet Astron. J., 14, 495.Google Scholar
Freeman, K.: 1970, Astrophys. J. 160, 811.Google Scholar
Fricke, W. and Tsioumis, A.: 1975, Astron. Astrophys., 42, 449.Google Scholar
Gunn, J. E.: 1977, Astrophys. J., 218, 592.Google Scholar
Harris, W. and Hesser, J.: 1976, Publ. Astron. Soc. Pacific, 88, 377.Google Scholar
Innanen, K.: 1973, Astrophys. Space Sci., 22, 393.CrossRefGoogle Scholar
Kormendy, J.: 1977a, Astrophys. J., 217, 406.Google Scholar
Kormendy, J.: 1977b, Astrophys. J., 218, 333.Google Scholar
Krumm, N. and Salpeter, E. E.: 1977, Astron. Astrophys., 56, 465.Google Scholar
Oemler, G.: 1976, Astrophys. J., 209, 693.Google Scholar
Oort, J.: 1960,Google Scholar
Oort, J.: 1965, Stars & Stellar Systems V, p. 483 (U of Chicago Press: Chicago).Google Scholar
Oort, J.: 1977, Astrophys. J., 218, L97.Google Scholar
Ostriker, J.P., Peebles, P.E.J. and Yahil, A.: 1974, Astrophys. J. Letters, 193, L1.CrossRefGoogle Scholar
Ostriker, J.P. and Thuan, T.X.: 1975, Astrophys. J., 202, 353.CrossRefGoogle Scholar
Plaut, L. and Oort, J.: 1975, Astron. Astrophys., 41, 71.Google Scholar
Roberts, M.S.: 1974, Rotation Curve of Galaxies, in Dynamics of Stellar Systems, ed. Hayli, A. (Reidel Pub.: Dordrecht), 331 Google Scholar
Rougoor, G. and Oort, J.: 1960, Proc. Nat. Acad. Sci., 46, 1.CrossRefGoogle Scholar
Rubin, V.C., Ford, W.K. and Thonnard, N.: 1978, preprint.Google Scholar
Salpeter, E.E.: 1977, IAU Symp. No. 77.Google Scholar
Schmidt, J.: 1965, Stars & Stellar Systems, V, 513 (U of Chicago Press: Chicago).Google Scholar
Scoville, N.Z. and Solomon, P.M.: 1975, Astrophys. J., 199, L105.Google Scholar
Spinrad, H., Ostriker, J.P., Stone, R.P.S., Chiu, G.L-T. and Bruzual, A.: 1978, Astrophys. J., in press.Google Scholar
Toomre, A.: 1972, Quart. J. Roy. Astron. Soc., 13, 241.Google Scholar
Tremaine, S.D.: 1976, Astrophys. J., 203, 345.Google Scholar
Turner, E.L.: 1976, Astrophys. J., 208, 304.Google Scholar
Tuve, M. and Lundsager, S.: 1973, Velocity Structures in Hydrogen Profiles, Carnegie Inst. of Washington Publ. 630.Google Scholar
Vandervoort, P.: 1970, Astrophys. J., 162, 453.Google Scholar
Vasilevskis, S. and Klemola, A.: 1971, Astron. J., 76, 508.Google Scholar
Weistrop, D.: 1972, Astron. J., 77, 366.CrossRefGoogle Scholar