Disruption of satellites in cosmological haloes

The Ultra Compact Dwarf (UCD) galaxies recently discovered in the Fornax and Virgo clusters exhibit structural similarity to the dense nuclei of nucleated dEs indicating that the progenitor galaxy and its halo have been entirely tidally disrupted. Using high resolution $N$-body simulations with up to ten million particles we investigate the evolution and tidal stripping of substructure halos orbiting within a host potential. We find that complete disruption of satellite halos...

We present the findings of a comprehensive and detailed analysis of merger tree data from ultra-high-resolution cosmological $N$-body simulations. The analysis, conducted with a particle mass resolution of $5 \times 10^3 h^{-1} M_{\odot}$ and a halo mass resolution of $10^7 h^{-1} M_{\odot}$, provides sufficient accuracy to suppress numerical artefacts. This study elucidates the dynamical evolution of subhaloes associated with the Milky Way-like host haloes. Unlike more massi...

The evolution of a satellite galaxy of a Milky Way like galaxy has been studied using N-Body simulations. The initial satellites, containing one million particles, have been simulated by a Plummer sphere, while the potential of the host galaxy is a three component rigid potential: disc, bulge and dark matter halo. It has been found that several orbits of the satellites allow for the existence, for about 1 Gyr or more, of an out-of-equilibrium body that could be interpreted as...

We describe an algorithm for constructing N-body realizations of equilibrium spherical systems. A general form for the mass density rho(r) is used, making it possible to represent most of the popular density profiles found in the literature, including the cuspy density profiles found in high-resolution cosmological simulations. We demonstrate explicitly that our models are in equilibrium. In contrast, many existing N-body realizations of isolated systems have been constructed...

We study tidal stripping of fuzzy dark matter (FDM) subhalo cores using simulations of the Schr\"{o}dinger-Poisson equations and analyze the dynamics of tidal disruption, highlighting the differences with standard cold dark matter. Mass loss outside of the tidal radius forces the core to relax into a less compact configuration, lowering the tidal radius. As the characteristic radius of a solitonic core scales inversely with its mass, tidal stripping results in a runaway effec...

A variety of new physical processes have proven to play an important role in orbital decay of a satellite galaxy embedded inside a dark matter halo but this is not fully understood. Our goal is to assess if the orbital history of a satellite remains unchanged during a concurrent sinking. For this purpose we analyze the impact that the internal structure of the satellites and their spatial distribution inside the host halo may have on the concurrent sinking process due to both...

We use N-body simulations to study the evolution of cuspy cold dark matter (CDM) halos in the gravitational potential of a massive host. Tidal mass losses reshape CDM halos, leaving behind bound remnants whose characteristic densities are set by the mean density of the host at the pericentre of their respective orbit. The evolution to the final bound remnant state is essentially complete after ~5 orbits for nearly circular orbits, while reaching the same remnant requires ~25 ...

A fully analytical formulation is developed to make dynamical friction modeling more realistic. The rate for a satellite to decay its orbit in a host galaxy halo is often severely overestimated when applying ChandraSekhar's formula without correcting for the tidal loss of the satellite and the adiabactic growth of the host galaxy potential over the Hubble time. As a satellite decays to the inner and denser region of the host galaxy, the high ambient density speeds up their ex...

We use the ``Via Lactea'' simulation to study the co-evolution of a Milky Way-size LambdaCDM halo and its subhalo population. While most of the host halo mass is accreted over the first 6 Gyr in a series of major mergers, the physical mass distribution [not M_vir(z)] remains practically constant since z=1. The same is true in a large sample of LambdaCDM galaxy halos. Subhalo mass loss peaks between the turnaround and virialization epochs of a given mass shell, and declines af...

We develop a model for the growth of dark matter halos and use it to study their evolved density profiles. In this model, halos are spherical and form by quiescent accretion of matter in clumps, called satellites. The halo mass as a function of redshift is given by the mass of the most massive progenitor, and is determined from Monte-Carlo realizations of the merger-history tree. Inside the halo, satellites move under the action of the gravitational force of the halo and a dy...