Properties of strongly magnetized ultradense matter and their imprints on magnetar pulsations

TL;DR

This paper studies how extremely strong magnetic fields inside neutron stars affect their pulsation frequencies, suggesting that these effects could be observed in magnetar flare lightcurves to probe ultradense matter.

Contribution

It introduces a model for magnetized hadronic matter and calculates the impact of intense magnetic fields on neutron star pulsation modes, highlighting potential observational signatures.

Findings

Magnetic fields up to 3 x 10^{18} G significantly alter pulsation frequencies.

Radial pulsations could imprint observable signals in magnetar flare lightcurves.

Magnetized ultradense matter affects neutron star oscillation properties.

Abstract

We investigate the effect of strong magnetic fields on the adiabatic radial oscillations of hadronic stars. We describe magnetized hadronic matter within the framework of the relativistic nonlinear Walecka model and integrate the equations of relativistic radial oscillations to determine the fundamental pulsation mode. We consider that the magnetic field increases, in a density dependent way, from the surface, where it has a typical magnetar value of $10^{15}$ G, to the interior of the star where it can be as large as $3 \times 10^{18}$ G. We show that magnetic fields of the order of $10^{18}$ G at the stellar core produce a significant change in the frequency of neutron star pulsations with respect to unmagnetized objects. If radial pulsations are excited in magnetar flares, they can leave an imprint in the flare lightcurves and open a new window for the study of highly magnetized ultradense matter.