We use hydrodynamical simulations of galaxy clusters and groups to study the effect of pre–heating on the entropy structure of the intra–cluster medium (ICM). Our simulations account for non–gravitational heating of the gas either by imposing a minimum entropy floor at redshift zh = 3 in adiabatic simulations, or by considering feedback by galactic winds powered by supernova (SN) energy in runs...

Future fusion reactors will require high divertor and core radiation by impurity seeding to limit divertor heat loads. In addition, high core densities are required to maximize the fusion power. A well established technique to reduce heat loads on divertor target plates is to insert low and medium Z impurities in the plasma to convert the heat flux into radiation [1]. Radiative cooling by nitro...

High resolution X-ray observations indicate that the entropy profiles in the central regions of some massive cooling flow clusters are well approximated by powerlaws. McCarthy and coworkers recently accounted for this trend with an analytic model that includes the detailed effects of radiative cooling. Interestingly, these authors found that cooling (and subsequent inflow of the gas) naturally ...

Atmospheric Emitted Radiance Interferometer (AERI) spectra provide detailed characterization of the infrared component of the surface radiation budget (Ellingson et al. 1995), support spectroscopic (Clough et al. 1989; Revercomb et al. 1995) and cloud (Smith et al. 1992; Collard et al. 1995) radiative modeling studies for improving radiative transfer calculations, and are the basis for high tim...

There is a growing interest in incorporating multiply scattered waves into modeling the Earth’s interior using radiative transfer theory. For thin beds, we derive the equivalence of the exponential decay of the transmitted wave predicted by the O’Doherty-Anstey formula with the coherent wave obtained from radiative transfer. This shows an underlying relationship between mean field theory and ra...

We use the semi-analytical program RCFORGV to evaluate radiative corrections to one-photon radiative emission in the high-energy scattering of pions in the Coulomb field of a nucleus with atomic number Z. It is shown that radiative corrections can simulate a pion polarizability effect. The average effect is α π = −β π = (0.20±0.05)×10cm, for pion energies 40-600 GeV. We also study the range of ...

[1] Aerosols absorb solar radiation thus changing the atmospheric temperature profile but the overall magnitude of this effect is not known. To that end, Saharan dust emissions over the Atlantic Ocean provide an opportunity to examine aerosol-related heating via satellite imaging. A major difficulty, however, is disentangling a straightforward heating signal caused by the absorbing dust from a ...

We present results from a new set of 30 cosmological simulations of galaxy clusters, including the effects of radiative cooling, star formation, supernova feedback, black hole growth and AGN feedback. We first demonstrate that our AGN model is capable of reproducing the observed cluster pressure profile at redshift, z ≃ 0, once the AGN heating temperature of the targeted particles is made to sc...

Recent observations of M87 and some blazars reveal violent activity in small regions located at relatively large distances from the central engine. Motivated by these considerations, we study the hydrodynamic collimation of a relativistic cooling outflow using a semi-analytical model developed earlier. We first demonstrate that radiative cooling of the shocked outflow layer can lead to a focusi...