Arianna DiCintio

The density profile of subhaloes in the CLUES simulation: implication for the MIlky Way's dwarf spheroidals
Wann Am 15.05.2012 von 11:00 bis 12:00
Was
  • Special Seminar
Wo LH, Hörsaal
Termin übernehmen vCal / iCal

We use dark matter only and full hydrodynamical Constrained Local UniversE Simulations (CLUES) of the formation of the Local Group to study the density profile of subhaloes of the simulated Milky Way and Andromeda galaxies. We show that the Einasto model provides the best description of the subhaloes’ density profile, as opposed to the more commonly used NFW profile or any generalization of it. We further find that the Einasto shape parameter n_E is strongly correlated with the total subhalo mass, pointing towards the notion of a non-universality of the subhaloes’ density +profile. Assuming now that the dSphs of our Galaxy thus follow the Einasto profile and using the maximum and minimum values of n_E from our SPH simulations as a gauge, we can improve the observational constraints on the R_max-V_max pairs obtained for the brightest satellit +galaxies of the Milky Way. When considering only the subhaloes with -13.2  < M_V < -8.8, i.e. the range of luminosity of the classical +dwarfs, we find that all our simulated objects are consistent with the observed dSphs if their haloes follow the Einasto model with 1.6<n_E<5.3. The numerically motivated Einasto profile for the observed dSphs as well as the observationally motivated magnitude cut for the simulated subhaloes will eliminate the ”massive failures” problem and results in a perfect agreement with observations, if the Milky Way mass is ~8x10^11 Msun.