Soft X-ray Polarization in Thermal Magnetar Emission - Astrophysics > High Energy Astrophysical PhenomenaReportar como inadecuado




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Abstract: Emission spectra from magnetars in the soft X-ray band likely contain athermal component emerging directly from the neutron star surface. However, thelack of observed absorption-like features in quiescent spectra makes itdifficult to directly constrain physical properties of the atmosphere. We arguethat future X-ray polarization measurements represent a promising technique fordirectly constraining the magnetar magnetic field strength and geometry. Weconstruct models of the observed polarization signal from a finite surfacehotspot, using the latest NS atmosphere models for magnetic fields B = 4 x10^13-5 x 10^14 G. Our calculations are strongly dependent on the NS magneticfield strength and geometry, and are more weakly dependent on the NS equationof state and atmosphere composition. We discuss how the complementarydependencies of phase-resolved spectroscopy and polarimetry might resolvedegeneracies that currently hamper the determination of magnetar physicalparameters using thermal models.



Autor: Matthew van Adelsberg, Rosalba Perna

Fuente: https://arxiv.org/







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