5 research outputs found
Gravitational radiation from pulsar glitches
The nonaxisymmetric Ekman flow excited inside a neutron star following a
rotational glitch is calculated analytically including stratification and
compressibility. For the largest glitches, the gravitational wave strain
produced by the hydrodynamic mass quadrupole moment approaches the sensitivity
range of advanced long-baseline interferometers. It is shown that the
viscosity, compressibility, and orientation of the star can be inferred in
principle from the width and amplitude ratios of the Fourier peaks (at the spin
frequency and its first harmonic) observed in the gravitational wave spectrum
in the plus and cross polarizations. These transport coefficients constrain the
equation of state of bulk nuclear matter, because they depend sensitively on
the degree of superfluidity.Comment: 28 page
Continuous-wave gravitational radiation from pulsar glitch recovery
Nonaxisymmetric, meridional circulation inside a neutron star, excited by a
glitch and persisting throughout the post-glitch relaxation phase, emits
gravitational radiation. Here, it is shown that the current quadrupole
contributes more strongly to the gravitational wave signal than the mass
quadrupole evaluated in previous work. We calculate the signal-to-noise ratio
for a coherent search and conclude that a large glitch may be detectable by
second-generation interferometers like the Laser Interferometer
Gravitational-Wave Observatory. It is shown that the viscosity and
compressibility of bulk nuclear matter, as well as the stratification
length-scale and inclination angle of the star, can be inferred from a
gravitational wave detection in principle.Comment: 19 pages, 4 figures, accepted for publication in MNRA
Gravitational waves from single neutron stars: an advanced detector era survey
With the doors beginning to swing open on the new gravitational wave
astronomy, this review provides an up-to-date survey of the most important
physical mechanisms that could lead to emission of potentially detectable
gravitational radiation from isolated and accreting neutron stars. In
particular we discuss the gravitational wave-driven instability and
asteroseismology formalism of the f- and r-modes, the different ways that a
neutron star could form and sustain a non-axisymmetric quadrupolar "mountain"
deformation, the excitation of oscillations during magnetar flares and the
possible gravitational wave signature of pulsar glitches. We focus on progress
made in the recent years in each topic, make a fresh assessment of the
gravitational wave detectability of each mechanism and, finally, highlight key
problems and desiderata for future work.Comment: 39 pages, 12 figures, 2 tables. Chapter of the book "Physics and
Astrophysics of Neutron Stars", NewCompStar COST Action 1304. Minor
corrections to match published versio