We use the “Millennium Simulation” to study the mass function of accreted sub-halos during merger events in the dark halo assembly history. Our study includes three kinds of sub-halo mergers: (1) mergers that happen to the main progenitor of dark halos; (2) mergers that happen on the entire merging history tree of dark halos; and (3) mergers that leave identifiable sub-halos in present-day dark...

The thermal plasma of galaxy clusters lost most of its information on how structure formation proceeded as a result of dissipative processes. In contrast, non-equilibrium distributions of cosmic rays (CR) preserve the information about their injection and transport processes and provide thus a unique window of current and past structure formation processes. This information can be unveiled by o...

The thermal plasma of galaxy clusters lost most of its information on how structure formation proceeded as a result of dissipative processes. In contrast, non-equilibrium distributions of cosmic rays (CR) preserve the information about their injection and transport processes and provide thus a unique window of current and past structure formation processes. This information can be unveiled by o...

We investigate how the shapes and angular momenta of galaxy and group mass dark matter halos in a ΛCDM N -body simulation are correlated internally, and how they are aligned with respect to the location and properties of surrounding halos. We explore these relationships down to halos of much lower mass (10 h−1 M⊙) than previous studies. The halos are triaxial, with c/a ratios of 0.6± 0.1 and a ...

The gravitational lensing constraints on the small mass end of the ΛCDM mass function are discussed. Here a conservative approach is taken where only the most difficult to explain image flux anomalies in strong QSO lenses are emphasized. Numerical simulations are performed to compare predictions for the ΛCDM small scale mass function with the observed flux ratios. It is found that the cusp caus...

We study the dependence of the galaxy contents within halos on the halo formation time using two galaxy formation models, one being a semianalytic model utilizing the halo assembly history from a high resolution N-body simulation and the other being a smoothed particle hydrodynamics simulation including radiative cooling, star formation, and energy feedback from galactic winds. We confirm the f...

We study the dependence of galaxy contents within halos on halo formation time using two galaxy formation models, one being a semi-analytic model utilizing halo assembly history from a high resolution N-body simulation and the other being a smoothed particle hydrodynamics simulation including radiative cooling, star formation, and energy feedback from galactic winds. We confirm the finding by G...

We give a review of different properties of dark matter halos. Taken from different publications, we present results on (1) the mass and velocity functions, (2) density and velocity profiles, and (3) concentration of halos. The results are not sensitive to parameters of cosmological models, but formally most of them were derived for popular flat ΛCDM model. In the range of radii r = (0.005 − 1)...

I present an analysis of the density shapes of dark matter halos in ΛCDM and ΛWDM cosmologies. The main results are derived from a statistical sample of galaxy-mass halos drawn from a high resolution ΛCDM N-body simulation. Halo shapes show significant trends with mass and redshift: low-mass halos are rounder than high mass halos, and, for a fixed mass, halos are rounder at low z. Contrary to p...

We investigate the spin alignment of dark matter halos by considering a mechanism somewhat similar to tidal locking. dubbed it Tidal Locking Theory (TLT). While Torque is responsible for initial angular momentum halos, locking explains evolution during non-linear ages. Our previous work showed that close encounters between haloes could drastically change their momentum. The current manuscript a...