相关论文: Gravitational diffusion in the intra-cluster mediu…
We present results on the heating of the inter-cluster medium (ICM) by gravitational potential energy from in-falling satellites. We calculate the available excess energy of baryons once they are stripped from their satellite and added to…
While the concept of "clustering" primarily refers to galaxies, the fact is that galaxies can be neglected - at least in terms of mass - when considering the continuous competition between accretion and relaxation processes of dark matter…
Many galaxy clusters pose a "cooling-flow problem", where the observed X-ray emission from their cores is not accompanied by enough cold gas or star formation. A continuous energy source is required to balance the cooling rate over the…
Clusters of galaxies are self-gravitating systems of mass ~10^14-10^15 Msun. They consist of dark matter (~80 %), hot diffuse intracluster plasma (< 20 %) and a small fraction of stars, dust, and cold gas, mostly locked in galaxies. In most…
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…
In massive objects, such as galaxy clusters, the turbulent velocity dispersion, $\sigma_\mathrm{turb}$, is tightly correlated to both the object mass, $M$, and the thermal energy. Here, we investigate whether these scaling laws extend to…
We revisit the phenomenon of elements diffusion in the intergalactic medium (IGM) in clusters of galaxies. The diffusion is driven by gravity, concentration and temperature gradients. The latter cause thermal diffusion, which has been so…
The time scale for cooling of the gravitationally bound gaseous intracluster medium (ICM) is not determined by radiative processes alone. If the ICM is in quasi-hydrostatic equilibrium in the fixed gravitational field of the dark matter…
X-ray observations indicate that non-gravitational processes play a key role in determining the distribution of the diffuse, X-ray emitting gas in clusters of galaxies (ICM). The effect of non-gravitational processes is imprinted in the ICM…
We explore the effect of magnetorotational turbulence on the dynamics and concentrations of boulders in local box simulations of a sub-Keplerian protoplanetary disc. The solids are treated as particles each with an independent space…
In this paper we investigate the convection phenomenon in the intracluster medium (the weakly-collisional magnetized inhomogeneous plasma permeating galaxy clusters) where the concentration gradient of the Helium ions is not ignorable. To…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is determined by gravitational processes associated with shock heating, adiabatic compression, and non-gravitational processes such as heating by SNe, stellar…
Recent observations of Jupiter and Saturn provided by spacecraft missions, such as Juno and Cassini, compel us to revise and improve our models of giant planet interiors. Even though hydrogen and helium are by far the dominant species in…
We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the evolution of cluster galaxies. We calculate the evolution of clusters by combining the…
It is widely believed that structure in the Universe evolves hierarchically, as primordial density fluctuations, amplified by gravity, collapse and merge to form progressively larger systems. The structure and evolution of X-ray clusters,…
Understanding whether Helium can sediment to the core of galaxy clusters is important for a number of problems in cosmology and astrophysics. All current models addressing this question are one-dimensional and do not account for the fact…
The gas in galaxy clusters is heated by shock compression through accretion (outer shocks) and mergers (inner shocks). These processes additionally produce turbulence. To analyse the relation between the thermal and turbulent energies of…
Element settling inside the Sun now becomes detectable from the comparison of the observed oscillation modes with the results of the theoretical models. This settling is due, not only to gravitation, but also to thermal diffusion and…
Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular…
The strong deviation in the properties of X-ray clusters from simple scaling laws highlights the importance of non-gravitational heating and cooling processes in the evolution of proto-cluster gas. We investigate this from two directions:…