Abstract

BENAVIDES BLANCO, José  and  CASAS-MIRANDA, Rigoberto A.. Numerical simulations of the formation of the Milky Way disk of satellites through the accretion of associations of dwarf galaxies. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2018, vol.42, n.162, pp.32-40. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.561.

We present here the results of several numerical Newtonian N-body simulations of the accretion towards the Milky Way of associations of dwarf spheroidal galaxies with and without dark matter content. We generated the initial objects using ZENO and simulated an isolated environment where these associations fall towards the dark matter halo of the Milky Way using GADGET-2. In order to test if the disk of satellites of the Milky Way (DoS) could have been formed by that kind of accretions, we analyzed some characteristics of the final dwarf galaxies such as their distribution with respect to the disk of the Galaxy, their density profile, velocity dispersion and radial velocities. The associations were initially located at radial distances of 4, 2 y 1 Mpc from the center of the Milky Way, and the evolution of the system was simulated for 10 Gyr in each of the runs. We found that associations located at initial radial distances larger than 2 Mpc were not suitable because their time of infall was larger than a Hubble time, and that for the case of associations initially located at 1 Mpc from the center of the Milky Way, it is unlikely that, with the parameters used in this study, the satellites of the DoS could come from dark matter-free associations of dwarf galaxies, while it is possible that the DoS may have been formed by the infall of associations of dwarf galaxies embedded in dark matter haloes following parabolic orbits. However, the distances of the remnants at the final snapshot do not reproduce those reported in the literature for the satellites of the Milky Way.

Keywords : Milky Way; Dwarf galaxies; Dark matter halo; Disk of satellites..

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