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Date and Time of the Query: 2019-07-22 T11:09:25 PDT
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For refcode 2014MNRAS.439.2132R:
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Copyright by Royal Astronomical Society. 2014MNRAS.439.2132R Galaxy mass models: MOND versus dark matter haloes Randriamampandry, Toky H.; Carignan, Claude Abstract. Mass models of 15 nearby dwarf and spiral galaxies are presented. The galaxies are selected to be homogeneous in terms of the method used to determine their distances, the sampling of their rotation curves (RCs) and the mass-to-light ratio (M/L) of their stellar contributions, which will minimize the uncertainties on the mass model results. Those RCs are modelled using the MOdified Newtonian Dynamics (MOND) prescription and the observationally motivated pseudo-isothermal (ISO) dark matter (DM) halo density distribution. For the MOND models with fixed M/L, better fits are obtained when the constant a_0_ is allowed to vary, giving a mean value of (1.13 +/- 0.50) x 10^-8^ cm s^-2^, compared to the standard value of 1.21 x 10^-8^ cm s^-2^. Even with a_0_ as a free parameter, MOND provides acceptable fits (reduced chi ^2^_r < 2) for only 60 per cent (9/15) of the sample. The data suggest that galaxies with higher central surface brightnesses tend to favour higher values of the constant a_0_. This poses a serious challenge to MOND since a_0_ should be a universal constant. For the DM models, our results confirm that the DM halo surface density of ISO models is nearly constant at {rho}_0_ R_C_ ~ 120 M_&sun;_ pc^-2^. This means that if the M/L is determined by stellar population models, ISO DM models are left with only one free parameter, the DM halo central surface density. Key words: galaxies: dwarf, galaxies: kinematics and dynamics, galaxies: spiral, galaxies: structure, dark matter
Retrieve 15 NED objects in this reference.
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