TORSIONAL NODELESS VIBRATIONS OF A QUAKING NEUTRON STAR RESTORED BY THE COMBINED FORCES OF SHEAR ELASTIC AND MAGNETIC FIELD STRESSES
| Autor: | G.-T. Chen, H. K. Chang, Irina Molodtsova, Sergey Bastrukov, D. V. Podgainy |
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| Rok vydání: | 2008 |
| Předmět: |
Physics
Toroid Magnetic moment Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Mechanics Astrophysics Magnetar Magnetic field Shear (sheet metal) Dipole Neutron star Space and Planetary Science Newtonian fluid Astrophysics::Solar and Stellar Astrophysics |
| Zdroj: | The Astrophysical Journal. 690:998-1005 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.1088/0004-637x/690/1/998 |
| Popis: | Within the framework of Newtonian magneto-solid-mechanics, relying on equations appropriate for a perfectly conducting elastic continuous medium threaded by a uniform magnetic field, the asteroseismic model of a neutron star undergoing axisymmetric global torsional nodeless vibrations under the combined action of Hooke's elastic and Lorentz magnetic forces is considered with emphasis on a toroidal Alfv\'en mode of differentially rotational vibrations about the dipole magnetic moment axis of the star. The obtained spectral equation for frequency is applied to $\ell$-pole identification of quasi-periodic oscillations (QPOs) of X-ray flux during the giant flares of SGR 1806-20 and SGR 1900+14. Our calculations suggest that detected QPOs can be consistently interpreted, within the framework of this model, as produced by global torsional nodeless vibrations of quaking magnetar if they are considered to be restored by the joint action of bulk forces of shear elastic and magnetic field stresses. Comment: 18 pages, 5 figures; accepted in ApJ |
| Databáze: | OpenAIRE |
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