Portal de Periódicos da CAPES

Density profiles of dark matter halos in an improved secondary infall model

2000; EDP Sciences; Volume: 353; Linguagem: Inglês

1432-0746

Antonino Del Popolo, M. Gambera, Erasmo Recami, E. Spedicato, Viale A. Doria, Piazza Rosate, Viale G. Marconi,

Scientific Research and Discoveries

In this paper we calculate the density profiles of viri- alized halos both in the case of structure evolving hierarchically from a scale-free Gaussian field having a power spectrum P(k) / k n in a =1 Universe and in the case of the CDM model, by using a modified version of Hoffman & Shaham's (1985) (hereafter HS) and Hoffman's (1988) model. We sup- pose that the initial density contrast profile around local max- ima is given by the mean peak profile introduced by Bardeen et al. (1986) (hereafter BBKS), and is not just proportional to the two-point correlation function, as assumed by HS. We show that the density profiles, both for scale-free Universes and the CDM model, are not power-laws but have a logarithmic slope that in- creases from the inner halo to its outer parts. Both scale-free, for n 1, and CDM density profiles are well approximated by Navarro et al. (1995, 1996, 1997) profile. The radius a ,a t which the slope = 2, is a function of the mass of the halo and in the scale-free models also of the spectral index n.