Related papers: A universal density slope - velocity anisotropy re…
This is the fifth in a series of papers studying the astrophysics and cosmology of massive, dynamically relaxed galaxy clusters. Our sample comprises 40 clusters identified as being dynamically relaxed and hot in Papers I and II of this…
The rotation curves of dark matter dominated dwarf galaxies are analysed. The observations show that dark matter halos represent a one-parameter family with self similar density profiles. The global halo parameters, like total mass and…
The Cold Dark Matter paradigm successfully explains many phenomena on scales larger than galaxies, but seems to predict galaxy halos which are more centrally concentrated and have a lumpier substructure than observed. Endowing cosmic dark…
We use N-body simulations to study the velocity bias of dark matter halos, the difference in the velocity fields of dark matter and halos, in a flat low- density LCDM model. The high force, 2kpc/h, and mass, 10^9Msun/h, resolution allows…
The scalar field endowed with a cosh scalar field potential, behaves exactly in the same way as cold dark matter (CDM) in the region where the scalar field oscillates around its minimum. Also, in the linear regime, the scalar field dark…
We study the stability of a spherically symmetric density profile. We analyze the case of a collisionless system with a power-law profile given by rho propto r^-alpha, in the Newtonian regime using the Jeans equation. The Jeans equation is…
The velocity anisotropy profiles, $\beta(r)$, of galaxy clusters are directly related to the shape of the orbits of their member galaxies. Knowledge of $\beta(r)$ is important to understand the assembly process of clusters and the…
We present multi-tracer dynamical models of the low mass ($M_{*} \sim 10^{7}$), isolated dwarf irregular galaxy WLM in order to simultaneously constrain the inner slope of the dark matter (DM) halo density profile ($\gamma$) and flattening…
Using adaptive mesh-refinement cosmological hydrodynamic simulations with a physically motivated supernova feedback prescription we show that the standard cold dark matter model can account for extant observed properties of damped Lyman…
We investigate the mass ($M_{200}$) and concentration ($c_{200}$) dependencies of the velocity anisotropy ($\beta$) profiles for different components in the dark matter halo, including halo stars, dark matter and subhalos, using systems…
Numerous numerical studies indicate that dark matter halos show an almost universal radial density profile. The origin of the profile is still under debate. We investigate this topic and pay particular attention to the velocity dispersion…
Collisionless self-gravitating systems such as cold dark matter halos are known to harbor universal density profiles despite the intricate non-linear physics of hierarchical structure formation in the $\Lambda$CDM paradigm. The origin of…
We study velocity moments of elliptical galaxies in the Coma cluster using Jeans equations. The dark matter distribution in the cluster is modelled by a generalised formula based upon the results of cosmological N-body simulations. Its…
We provide new constraints on the connection between galaxies in the local universe, identified by the Sloan Digital Sky Survey (SDSS), and dark matter halos and their constituent substructures in the $\Lambda$CDM model using WMAP7…
We develop a flexible set of action-based distribution functions (DFs) for stellar haloes. The DFs have five free parameters, controlling the inner and outer density slope, break radius, flattening and anisotropy respectively. The DFs…
We use the secondary infall model described in Del Popolo (2009), which takes into account the effect of dynamical friction, ordered and random angular momentum, baryons adiabatic contraction and dark matter baryons interplay, to study how…
We define new potential-density pairs and examine the impact of the potential flattening on the vertical velocity ellipsoid tilt, $\delta$. By means of numerical integrations and analytical calculations, we estimate $\delta$ in a variety of…
We use a set of high-resolution cosmological N-body simulations to investigate the inner mass profile of galaxy-sized cold dark matter (CDM) halos. These simulations extend the thorough numerical convergence study presented in Paper I of…
f(R) gravity is thought to be an alternative to dark energy which can explain the acceleration of the universe. It has been tested by different observations including type Ia supernovae (SNIa), the cosmic microwave background (CMB), the…
We study trends in the slope of the total mass profiles and dark matter fractions within the central half-light radius of 258 early-type galaxies, using data from the volume-limited ATLAS$^{\mathrm{3D}}$ survey. We use three distinct sets…