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Corrected analytical solutions describing the enhanced phase mixing of Alfven waves propagating in divergent stratified coronal structures are presented. These show that the enhanced phase mixing mechanism can dissipate Alfven waves at heights less than half that is predicted by the previous analytical solutions. The enhanced phase mixing of 0.1 Hz harmonic Alfven waves propagating in strongly divergent, H_b=5 Mm, stratified coronal structures, H_rho=50 Mm, can fulfill 100% of an active region heating requirement, by generating viscous heating fluxes of F_H~2100 J /m^2 /s. The Alfven waves in this configuration are fully dissipated within 20 Mm, which is six times lower than would occur as a result of standard phase mixing in uniform magnetic fields. This results in the heating scale height, s_H, being lowered by a factor of six, to less than half of an active regions density scale height. Using the corrected analytical solutions it was found that, for a given wave frequency, the generation of a heating scale height of s_H, Accepted by A&A - 24th September 2007

A young neutron star with large spin-down power is expected to be closely surrounded by an e+/- pair plasma maintained by the conversion of gamma-rays associated with the star's polar-cap and/or outer-gap accelerators. Cyclotron-resonance scattering by the e- and e+ within several radii of such neutron stars prevents direct observations of thermal X-rays from the stellar surface. Estimates are presented for the parameters of the Planck-like X-radiation which ultimately diffuses out through this region. Comparisons with observations, especially of apparent blackbody emission areas as a function of neutron star age, support the proposition that we are learning about a neutron star's magnetosphere rather than about its surface from observations of young neutron star thermal X-rays., Comment: 10 pages, 5 figures, in 4th AGILE Science Workshop, "X-ray and Gamma-ray Astrophysics of Galactic Sources," 2003 June 11-13, Rome

Modeling the dynamics of the quantum fluids within a spinning-down neutron star gives a description consistent with observed pulsar magnetic field evolution and spin-period "glitches." The long-standing problem of large predicted excesses in spin-down sustained pulsar heating from such models now see ms resolvable. However, the origin of some pulsar spin-period and pulse-shape modulations which have been interpreted as manifestations of very long period (~year) stellar precession is a crucial challenge to canonical neutron star models., Comment: 10 pages, 4 figures, Invited talk at van Paradijs memorial conference

The present paper studies the heating of coronal loops by linear resonant Alfven waves that are excited by the motions of the photospheric footpoints of the magnetic field lines. The analysis is restricted to torsionally polarised footpoint motions in an axially symmetric system so that only torsional Alfven waves are excited. For this subclass of footpoint motions, the Alfven and cusp singularities are absent from the analysis which means that resonant coupling between global modes of the loop and localised oscillations is avoided. Instead, the focus is on the resonances due to the finite extent of the loop in the longitudinal direction: at the radii where Alfven waves travelling back and forth along the length of the loop are in phase with the footpoint motions, the oscillations grow unbounded in ideal MHD. Inclusion of electrical resistivity and viscosity as dissipation mechanisms prevents singular growth and we can look at the steady state in which the energy injected at the photospheric part of the loop is balanced by the energy dissipated at the dissipative layer around the resonance. In this sense, we show that the direct excitation of Alfven waves by torsionally polarised footpoint motions leads to a very efficient heating mechanism for coronal loops, even without resonant coupling to global modes.