Astrophysics.

Seismology of solar spicules based on Hinode/SOT observations

New Solutions for Singular Lane-Emden Equations Arising in Astrophysics Based on Shifted Ultraspherical Operational Matrices of Derivatives

In this paper, the ultraspherical operational matrices of derivatives are constructed. Based on these operational matrices, two numerical algorithms are presented and analyzed for obtaining new approximate spectral solutions of a class of linear and nonlinear Lane-Emden type singular initial value problems. The basic idea behind the suggested algorithms is basically built on transforming the eq...

Damping of visco-resistive Alfven waves in solar spicules

Interaction of Alfven waves with plasma inhomogeneity generates phase mixing which can cause the dissipation of Alfven waves. We investigated the dissipation of standing Alfven waves due to phase mixing at the presence of steady flow and sheared magnetic field in solar spicules. Moreover, the transition region between chromosphere and corona was considered. Our numerical simulation showed that ...

The Energy Dependence of the Photoelectric Attenuation Coefficient of Substances

Introduction: The photoelectric attenuation coefficient of substances is known to depend upon the energy E of the photon and the effective atomic number of substances (Zeff) as (Zeffx/Ey).  No definitive values about these indices x, y are given in the literature. The index x is said to lie between, 3.0 and 4.0, while for ‘y’ different values have been assigned, between 3.0 and 4.0. Method...

The Effect of Solar Particles in the Choice of Alloy Shielding in a Satellite

The damages and logical failures in dierent parts of a satellite may occur during a solar event, when a bulk of solar energetic particles approaching the Earth. During solar events, these particles may cause extensive damages which are even permanent (hard errors). A way of damage reduction is designing a proper coating as the fuselage. As protons are the major component of solar particles and ...

Laboratory Astrophysics: Enabling Scientific Discovery and Understanding

Laboratory Astrophysics: Enabling Scientific Discovery and Understanding Kate Kirby∗ ∗Harvard-Smithsonian Center for Astrophysics