Magnetar oscillations pose challenges for strange stars

Abstract

Compact relativistic stars allow us to study the nature of matter under extreme conditions, probing regions of parameter space that are otherwise inaccessible. Nuclear theory in this regime is not well constrained: one key issue is whether neutron stars are in fact composed primarily of strange quark matter. Distinguishing the two possibilities, however, has been difficult. The recent detection of seismic vibrations in the aftermath of giant flares from two magnetars (highly magnetized compact stars) is a major breakthrough. The oscillations excited seem likely to involve the stellar crust, the properties of which differ dramatically for strange stars. We show that the resulting mode frequencies cannot be reconciled with the observations for reasonable magnetar parameters. Ruling out strange star models would place a strong constraint on models of dense quark matter.

Parameter space expanded, 5 pages, 3 figures, MNRAS Letters in press

References in corpus (5)

• Neutron Star Asteroseismology. Axial Crust Oscillations in the Cowling Approximation
• Dense Matter in Compact Stars: Theoretical Developments and Observational Constraints
• On the theory of magnetar QPOs
• The Strange Star Surface: A Crust with Nuggets
• Neutron star oscillations and QPOs during magnetar flares

Cited by in corpus (4)

• Color superconductivity in dense quark matter
• Constraints on Neutron Star Crusts From Oscillations in Giant Flares
• Neutron star oscillations and QPOs during magnetar flares
• Thickness of the strangelet-crystal crust of a strange star