Related papers: Why do gallium clusters have a higher melting poin…
So far, six mechanisms have been proposed to account for the Galactic disk heating. Of these, the most important appear to be a combination of scattering of stars by molecular clouds and by spiral arms. We study a further mechanism, namely,…
The Galactic center is the closest region in which we can study star formation under extreme physical conditions like those in high-redshift galaxies. We measure the temperature of the dense gas in the central molecular zone (CMZ) and…
We studied by means of computer simulations the low temperature properties of two-dimensional parahydrogen clusters comprising between 7 and 30 molecules. Computed energetics is in quantitative agreement with that reported in the only…
We present a simple model to describe the dark matter density, the gas density, and the gas temperature profiles of galaxy clusters. Analytical expressions for these quantities are given in terms of only five free parameters with a clear…
We present high resolution X-ray spectra of 14 putative cooling-flow clusters of galaxies obtained with the Reflection Grating Spectrometer on XMM-Newton. The clusters in the sample span a large range of temperatures and mass deposition…
We introduce a method for classical trajectory calculations to simulate collisions between atoms and large rigid asymmetric-top molecules. Using this method, we investigate the formation of molecule-helium complexes in buffer-gas cooling…
Though feedback from central active galactic nuclei provides an attractive solution to the problem of overcooling in galaxy cluster cores, another possible source of heating may come from ``sloshing'' of the cluster core gas initiated by…
High-spectral resolution observations of clusters of galaxies are a powerful tool to understand the physical processes taking place in these massive objects. Their hot multi-million-degree X-ray emitting cluster atmospheres, containing most…
The virialization shock around an X-ray cluster primarily heats the ions, since they carry most of the kinetic energy of the infalling gas. Subsequently, the ions share their thermal energy with the electrons through Coulomb collisions. We…
We report the results of recent numerical simulations of the head-on merger of a cooling flow cluster with an infalling subcluster of galaxies. These simulations examined the effects of different types of cluster mergers (with 16:1 and 4:1…
Solving the kinetic equation for ionization-recombination processes in cold plasmas for temperatures much lower than the first ionization potentials, we derive an explicit expression for the bulk viscosity. We obtain that bulk viscosity can…
Among all the properties required for the design of the next generation of PCM (density, heat capacity, thermal expansion, latent energy, volume change upon melting, corrosion rate, etc.) the thermal transport properties are by far the…
The Chandra and XMM data for a sample of 19 relaxed groups/poor clusters, covering the temperature range 1-3 keV and selected to have the best available data, reveal a remarkable similarity in their temperature profile: cool cores outside…
Strong evidence for cooling flows has been found in low resolution X-ray imaging and spectra of many clusters of galaxies. However high resolution X-ray spectra of several clusters from the Reflection Grating Spectrometer (RGS) on…
There is no shortage of energy around to solve the overcooling problem of cooling flow clusters. AGNs, as well as gravitational energy are both energetic enough to balance the cooling of cores of clusters. The challenge is to couple this…
We investigate a non-equilibrium ionization state and an electron-ion two-temperature structure of the intracluster medium in the merging galaxy cluster, 1E0657-56 (the Bullet cluster), using a series of N-body and hydrodynamic simulations.…
Results from a large sample of hydrodynamical/N-body simulations of galaxy clusters in a LCDM cosmology are used to simulate cluster X-ray observations as expected from Chandra observations. The physical modeling of the gas includes…
We present results on the spectroscopic analysis of XMM-Newton EPIC data of the central 0.5/h_50 Mpc regions of the clusters of galaxies Coma, A1795 and A3112. The temperature of the hot intracluster gas as determined by modeling the 2 - 7…
An XMM-Newton observation of the cool (kT=2.1 keV) cluster A1983, at z=0.044, is presented. Gas density and temperature profiles are calculated for the inner 500 h_{50}^{-1} kpc (~0.35 r_200). The outer regions of the surface brightness…
The Curie temperature TC is investigated as a function of the hole concentration p in thin films of ferromagnetic semiconductor (Ga,Mn)As. The magnetic properties are probed by transport measurements and p is varied by the application of an…