相关论文: Mixed Dark Matter Model in Halos of Clusters
We report results from high-resolution particle-mesh (PM) N-body simulations of structure formation in an $\Omega=1$ cosmological model with a mixture of Cold plus Hot Dark Matter (C+HDM) having $\Omega_{\rm cold}=0.6$, $\Omega_\nu=0.3$,…
We present results of N-body/gasdynamical simulations designed to investigate the evolution of X-ray clusters in a flat, low-density, cold dark matter (CDM) cosmogony. The density profile of the dark matter component can be fitted rather…
Davidsen et al. (1991) have argued that the failure to detect uv photons from the dark matter DM) in cluster A665 excludes the decaying neutrino hypothesis. Sciama et al. (1993) argued that because of high central concentration the DM in…
We present two matched sets of five simulations each, covering five presently favored simple modifications to the standard cold dark matter (CDM) scenario. One simulation suite, with a linear box size of 75 Mpc/h, is designed for high…
We present extended simulations of the distribution of galaxy clusters in different dark matter models, using an optimized version of the Zel'dovich approximation. Six different dark matter models are studied: Standard CDM, Open CDM, Tilted…
We estimate the variance and the skewness of the cluster distribution in several dark matter (DM) models. The cluster simulations are based on the Zel'dovich approximation, the low computational cost of which allows us to run 50 random…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
We examine the properties of dark matter halos within a rich galaxy cluster using a high resolution simulation that captures the cosmological context of a cold dark matter universe. The mass and force resolution permit the resolution of 150…
The recent detection of a 3.5 keV X-ray line from the centres of galaxies and clusters by Bulbul et al. (2014a) and Boyarsky et al. (2014a) has been interpreted as emission from the decay of 7 keV sterile neutrinos which could make up the…
Studies of flux anomalies statistics and perturbations in stellar streams have the potential to constrain models of warm dark matter (WDM), including sterile neutrinos. Producing these constraints requires a parametrization of the WDM mass…
The cold dark matter (CDM) cosmological model unambigously predicts that a large number of haloes should survive as subhaloes when they are accreted into a larger halo. The CDM model would be ruled out if such substructures were shown not…
Warm Dark Matter (WDM) has been invoked to resolve apparent conflicts of Cold Dark Matter (CDM) models with observations on subgalactic scales. In this work we provide a new and independent lower limit for the WDM particle mass (e.g.…
According to the standard cold dark matter (CDM) cosmology, the structure of dark halos including those of galaxy clusters reflects their mass accretion history. Older clusters tend to be more concentrated than younger clusters. Their…
Discrepancies have emerged between the predictions of standard cold dark matter (CDM) theory and observations of clustering on sub-galactic scales. Warm dark matter (WDM) is a simple modification of CDM in which the dark matter particles…
Cosmological dark matter in the form of neutrinos with masses of up to a few electron volts is known as hot dark matter. After an historical review of the subject, this article considers constraints on hot dark matter from current data on…
We analyze the properties of dark matter halos in the cold-plus-warm dark matter cosmologies (CWDM). We study their dependence on the fraction and velocity dispersion of the warm particle, keeping the free-streaming scale fixed. To this end…
Using an analytic model calibrated against numerical simulations, we calculate the central densities of dark matter halos in a ``conventional'' cold dark matter model with a cosmological constant (LCDM) and in a ``tilted'' model (TLCDM)…
We present semi-analytical constraint on the amount of dark matter in the merging bullet galaxy cluster using the classical Local Group timing arguments. We consider particle orbits in potential models which fit the lensing data. {\it…
One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves in spiral galaxies. Due to the Pauli exclusion principle it…
Warm dark matter (WDM) might more easily account for small scale clustering measurements than the heavier particles typically invoked in Lambda cold dark matter (LCDM) cosmologies. In this paper, we consider a Lambda WDM cosmology in which…