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General Relativity and Quantum Cosmology, gr-qc
Abstract:
Glitches in the rotational frequency of a spinning neutron star could be
promising sources of gravitational wave signals lasting between a few {\mu}s to
a few weeks. The emitted signals and their properties depend upon the internal
properties of the neutron star. In stellar models that assume a super-fluid
core for the neutron star, the most important physical properties are the
viscosity of the super-fluid, the stratification of flow in the equilibrium
state and the adiabatic sound speed. Such models were previously studied by van
Eysden and Melatos (2008) and Bennett et al. (2010) following simple
assumptions on all contributing factors, in which the post-glitch relaxation
phase could be driven by the well-known process of 'Ekman pumping'. We explore
the hydrodynamic properties of the flow of super-fluid during this phase
following more relaxed assumptions on the stratification of flow and/or the
pressure-density gradients within the neutron star than previously studied. We
calculate the time-scales of duration as well as the characteristic strengths
of the resulting gravitational wave signals, and we detail their dependence on
the physical properties of the super-fluid core. We find that it is possible
for the neutron star to emit gravitational wave signals in a wide range of
decay time-scales and within the detection sensitivity of aLIGO for selected
domains of physical parameters.
