G. Belvedere

Surface density of dark matter haloes on galactic and cluster scales

In this paper, in the framework of the secondary infall model, the correlation between the central surface density and the halo core radius of galaxy, and cluster of galaxies, dark matter haloes was analyzed, this having recently been studied on a wide range of scales. We used Del Popolo (2009) secondary infall model taking into account ordered and random angular momentum, dynamical friction, and dark matter (DM) adiabatic contraction to calculate the density profile of haloes, and then these profiles are used to determine the surface density of DM haloes. The main result is that

The origin of long‐period Alfvén waves in the solar wind

r_ast

How initial and boundary conditions affect protoplanetary migration in a turbulent sub-Keplerian accretion disc: 2D non-viscous SPH simulations

(the halo characteristic radius) is not an universal quantity as claimed by Donato et al. (2009) and Gentile et al. (2009). On the contrary, we find a correlation with the halo mass

Three-dimensional simulation of polytropic accretion discs

M_{200}

3D simulations of the SS Cyg accretion disc in the quiescent phase

in agreement with Cardone & Tortora (2010), Boyarsky at al. (2009) and Napolitano et al. (2010), but with a significantly smaller scatter, namely

A three-dimensional smoothed particle hydrodynamics simulation of the active phase of SS Cyg-type discs and its implications for the mass transfer burst model

0.16 pm 0.05

SUPERSONIC WIND ACCRETION IN MASSIVE CLOSE BINARY SYSTEMS : A 3D SPH SIMULATION OF CEN X-3

. We also consider the baryon column density finding this latter being indeed a constant for low mass systems such as dwarfs, but correlating with mass with a slope

Wind accretion in close binary systems: a 3D smoothed particle hydrodynamics simulation of disc structure and dynamics

alpha= 0.18 pm 0.05

Asymptotic dynamos in late-type stars

. In the case of the surface density of dark matter for a system composed only of dark matter, as in dissipationless simulations, we get

The 35-d modulation of the X-ray emission of Her X-1 in the framework of the SOD model: results of a three-dimensional SPH simulation

alpha=0.20 pm 0.05