We present detailed time and depth dependent chemical models of low mass dark molecular cloud cores. The cloud is assumed to be in hydrostatic equilibrium with a density and pressure structure described by a polytropic equation of state with negative polytropic index and boundary conditions at the centre and the edge of the cloud constrained by observations of dense and diffuse clouds. We study...

We have observed a typical Galactic plane field at (l, b) = (2846,−020) with Suzaku for 100 ksec to carry out a precise spectral study of the Galactic Ridge X-ray Emission (GRXE). The field is known to be devoid of X-ray point sources brighter than ∼2×10ergs s cm (2–10 keV), and already deeply observed with Chandra. Thanks to the low and stable background and high spectral resolution of Suzaku,...

Using N-body/hydrodynamic simulations, the influence of non-equipartition processes on the thermal and dynamical properties of cosmological baryonic gas is investigated. We focus on a possible departure from equilibrium between electrons, ions and neutral atoms in low temperature (10–10 K) and weakly ionized regions of the intergalactic medium. The simulations compute the energy exchanges betwe...

We present 74 MHz radio continuum observations of the Galactic center region. These measurements show nonthermal radio emission arising from molecular clouds that is unaffected by free–free absorption along the line of sight. We focus on one cloud, G0.13-0.13, representative of the population of molecular clouds that are spatially correlated with steep spectrum (α(327MHz)(74MHz) = 1.3 ± 0.3) no...

using the usual definitions of information and entropy in quantum gravity and statistical mechanics and the existing views about the relation between information and complexity, we examine the evolution of complexity in an ever expanding universe.

It is shown that a collection of photons with nearly the same frequency exhibits a Bose ”condensation” type of phenomenon at about 3K corresponding to a peak intensity at a wave length of about 0.4cm. This could give a mechanism for the observed Cosmic Background Radiation, and also explain some curious features. It is a curious circumstance that the substitution of the cosmic microwave backgro...

We argue that clusters of galaxies have an intergalactic medium, which is permeated by strong magnetic fields and also has a contribution of pressure from cosmic rays. These two components of total pressure are probably highly time dependent, and range probably between 1/10 of the gas pressure up to equipartition between gas pressure and the sum of the two other components. Radio galaxies are l...

In thermal leptogenesis, the cosmic matter-antimatter asymmetry is produced by CP violation in the decays N → l + Φ of heavy right-handed Majorana neutrinos N into ordinary leptons l and Higgs particles Φ. If some charged-lepton Yukawa couplings are in equilibrium during the leptogenesis epoch, the l interactions with the background medium are flavor sensitive and the coherence of their flavor ...

In the present paper, the phenomenological model developed by the authors in previous papers has been used to evaluate the degradation induced by hadron irradiation at the future accelerator facilities or by cosmic protons in high resistivity silicon detectors. The damage has been analysed at the microscopic (defects production and their evolution toward equilibrium) and at the macroscopic leve...

In this paper we investigate asymptotic isotropization. We derive the asymptotic dynamics of spatially inhomogeneous cosmological models with a perfect fluid matter source and a positive cosmological constant near the de Sitter equilibrium state at late times, and near the flat FL equilibrium state at early times. Our results show that there exists an open set of solutions approaching the de Si...