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Paper   IPM / P / 8244
School of Physics
  Title:   The Magellanic Stream in Modified Newtonian Dynamics
1.  H. Haghi
2.  S. Rahvar
3.  A. Hasani-Zonooz
  Status:   Published
  Journal: Astrophys. J
  Vol.:  354-361
  Year:  2006
  Pages:   652
  Supported by:  IPM
The dynamics of Magellanic Stream (MS) as a series of clouds extended from the Magellanic Clouds (MCs) to the south Galactic pole is affected by the distribution and the amount of matter in the Milky Way (MW). We calculate the gravitational effect of the Galactic disk on MS in the MOdified Newtonian Dynamics (MOND) frame work and compare with the observations of the radial velocity. We compare these results with that in the logarithmic and power-law dark halo models and show that the MOND theory seems plausible for describing the dynamics of satellite galaxies as MCs. A maximum likelihood analysis is used to obtain the best parameters of the MOND and the Galactic disk. On the other hand the gradient of column density on MS is modeled for a comoving observer using the MONDian hydrodynamical equilibrium of the gas and the gravitational force of MCs. We show that the observed profile of column density in MS is almost compatible with the model but the mass of the MCs results from this comparison is one order of magnitude less than our expectation. This result could be due to the dependence of the MONDian acceleration scale to the physical parameters of the system such as the size of the structure or in another word the non-universality of the acceleration scale of the MOND.

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