An Unstable Superfluid Stewartson Layer in a Differentially Rotating Neutron Star

Peralta, C.; Melatos, A.

doi:10.1088/0004-637x/701/2/l75

Cited by 20 publications

(24 citation statements)

References 38 publications

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“…Turbulence, on the other hand, is well known from laboratory superfluids and may play an important role in pulsar glitches (Peralta et al ; Melatos & Peralta ; Peralta & Melatos ) and could couple the superfluid and the normal component on inter‐glitch time‐scales in the presence of core pinning (Andersson, Sidery & Comer ). The inclusion of turbulence in a hydrodynamical glitch simulation is, however, a complex matter as not only is the nature of the turbulence not known (see e.g.…”

Section: Discussionmentioning

confidence: 99%

The effect of realistic equations of state and general relativity on the ‘snowplough’ model for pulsar glitches

Seveso

Pizzochero

Haskell

2012

Monthly Notices of the Royal Astronomical Society

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Many pulsars are observed to ‘glitch’, i.e. show sudden jumps in their rotational frequency ν, some of which can be as large as Δν/ν ≈ 10−6–10−5 in a subset of pulsars known as giant glitchers. Recently, Pizzochero has shown that an analytic model based on realistic values for the pinning forces in the crust and for the angular momentum transfer in the star can describe the average properties of giant glitches, such as the inter‐glitch waiting time, the step in frequency and that in frequency derivative. In this paper, we extend the model (originally developed in Newtonian gravity and for a polytropic equation of state) to realistic backgrounds obtained by integrating the relativistic equations of stellar structure and using physically motivated equations of state to describe matter in the neutron star. We find that this more detailed treatment still reproduces the main features of giant glitches in the Vela pulsar and allows us to set constraints on the equation of state. In particular, we find that stiffer equations of state are favoured and that it is unlikely that the Vela pulsar has a high mass (larger than M ≈ 1.5 M⊙).

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Section: Discussionmentioning

confidence: 99%

The effect of realistic equations of state and general relativity on the ‘snowplough’ model for pulsar glitches

Seveso

Pizzochero

Haskell

2012

Monthly Notices of the Royal Astronomical Society

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“…While it is unknown what triggers the collective unpinning, it is likely to excite a non-axisymmetric flow for two generic reasons. (1) Pinning causes the crust and superfluid to rotate differentially, inevitably driving non-axisymmetric meridional circulation and even turbulence, as observed in laboratory experiments (Munson & Menguturk 1975;Nakabayashi 1983;Junk & Egbers 2000) and numerical simulations (Peralta et al 2005(Peralta et al , 2006aMelatos & Peralta 2007;Peralta et al 2008;Peralta & Melatos 2009) of spherical Couette flow.…”

Section: Introductionmentioning

confidence: 99%

Continuous-wave gravitational radiation from pulsar glitch recovery

Bennett

Eysden

Melatos

2010

Monthly Notices of the Royal Astronomical Society

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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

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“…2 2 Peralta et al (2006b) showed that this is inaccurate at high Reynolds numbers, when meridional circulation and Kolmogorov‐like turbulence set in (Peralta & Melatos 2009; Melatos & Peralta 2010). …”

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confidence: 99%

Gravitational-wave bursts and stochastic background from superfluid vortex avalanches during pulsar glitches

Warszawski

Melatos

2012

Monthly Notices of the Royal Astronomical Society

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The current‐quadrupole gravitational‐wave signal emitted during the spin‐up phase of a pulsar glitch is calculated from first principles by modelling the vortex dynamics observed in recent Gross–Pitaevskii simulations of pinned, decelerating quantum condensates. Homogeneous and inhomogeneous unpinning geometries, representing creep‐ and avalanche‐like glitches, provide lower and upper bounds on the gravitational‐wave signal strength, respectively. The signal arising from homogeneous glitches is found to scale with the square root of glitch size, whereas the signal from inhomogeneous glitches scales proportional to glitch size. The signal is also computed as a function of vortex travel distance and stellar angular velocity. Convenient amplitude scalings are derived as functions of these parameters. For the typical astrophysical situation, where the glitch duration (in units of the spin period) is large compared to the vortex travel distance (in units of the stellar radius), an individual glitch from an object 1 kpc from Earth generates a wave strain of 10−24[(Δω/ω)/10−7](ω/102 rad s−1)3(Δr/10−2 m)−1, where Δr is the average distance travelled by a vortex during a glitch, Δω/ω is the fractional glitch size and ω is the pulsar angular velocity. The non‐detection of a signal from the 2006 Vela glitch in data from the fifth science run conducted by the Laser Interferometer Gravitational‐Wave Observatory implies that the glitch duration exceeds ∼10−4 ms. This represents the first observational lower bound on glitch duration to be obtained.

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An Unstable Superfluid Stewartson Layer in a Differentially Rotating Neutron Star

Cited by 20 publications

References 38 publications

The effect of realistic equations of state and general relativity on the ‘snowplough’ model for pulsar glitches

The effect of realistic equations of state and general relativity on the ‘snowplough’ model for pulsar glitches

Continuous-wave gravitational radiation from pulsar glitch recovery

Gravitational-wave bursts and stochastic background from superfluid vortex avalanches during pulsar glitches

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