We propose that the \textit{post-glitch} epoch in a Vela-type pulsar corresponds to a transition time in which the broken \textit{crust} is readjusting its temperature and core-\textit{crust} transition pressure after the changes produced by the \textit{glitch}. To describe the evolution of the pulsar in this epoch we use a sequence of stationary and axisymmetric relativistic models of slowly rotating neutron stars with a surface layer \textit{crust}. Previously, we have formulated the matching conditions on the surface of the star in terms of physical properties (total mass of the star, core-\textit{crust} transition pressure,...).
We revisit the short-term post-glitch relaxation of the Vela 2000 glitch in the simple two-component model of pulsar glitch by making use of the latest realistic equations of states from the microscopic Brueckner and the relativistic Brueckner theories for neutron stars, which can reconcile with the available astrophysical constraints. We show that to fit both the glitch size and the post-glitch jumps in frequency derivatives approximately one minute after the glitch, the mass of the Vela pulsar is necessarily small, and there may be demands for a stiff equation of state (which results in a ty…
The Crab and Vela are well-studied glitching pulsars and the data obtained sofar should enable us to test the reliability of models of their internal structures. Very recently it was proposed that glitching pulsars are embedded in bimetric spacetime: their incompressible superfluid cores (SuSu-cores) are embedded in flat spacetime, whereas the ambient compressible and dissipative media are enclosed in Schwarzschild spacetime. In this letter we apply this model to the Crab and Vela pulsars and show that a newly born pulsar initially of $1.25\text{M}_{\odot}$ and an embryonic SuSu-core of $0.029…
The 2016 Vela glitch observed by the Mt Pleasant radio telescope provides the first opportunity to study pulse-to-pulse dynamics of a pulsar glitch, opening up new possibilities to study the neutron star's interior. We fit models of the star's rotation frequency to the pulsar data, and present three new results. First, we constrain the glitch rise time to less than 12.6s with 90% confidence, almost three times shorter than the previous best constraint. Second, we find definitive evidence for a rotational-frequency overshoot and fast relaxation following the glitch. Third, we find evidence for …
Gravitational waves (GWs) can offer a novel window into the structure and dynamics of neutron stars. Here we present the first search for long-duration quasi-monochromatic GW transients triggered by pulsar glitches. We focus on two glitches observed in radio timing of the Vela pulsar (PSR J0835-4510) on 12 December 2016 and the Crab pulsar (PSR J0534+2200) on 27 March 2017, during the Advanced LIGO second observing run (O2). We assume the GW frequency lies within a narrow band around twice the spin frequency as known from radio observatons. Using the fully-coherent transient-enabled F-statisti…
We construct a two-component analytic model of the Vela pulsar which can reproduce the fractional crustal moment of inertia, $I_{\rm crust}/I_{\rm total} \geq 0.074$ ( where $I_{\rm crust}$ represents the moment of inertia of the crust and $ I_{\rm total}$ is the total moment of inertia of the star) for the mass range $M/M_\odot \geq 1.0 - 1.96$. The models are assumed to be self-bound at the surface density $E_a = 2\times 10^{14}\rm g{cm}^{-3}$ (like, Brecher and Caporaso \cite{Ref1}) which yields the transition density at the core-crust boundary $E_b \geq 2.105 \times 10^{14}\rm g{cm}^{-3}$ …
The core-envelope analytic models of Negi et al. (1989) have been found to be consistent with both the mechanisms of glitch generation in pulsars, namely - (i) the starquake model and (ii) the vortex unpinning model. In Negi (2019), the author has been able to reproduce the observed values of glitch healing parameter, $ G_h (= I_{\rm core}/I_{\rm total}; G_h$ represents the fractional moment of inertia of the core component in the starquake mechanism of glitch generation) for the Crab as well as for the Vela pulsar. In another study, by using the models discussed in Negi et al. (1989), the aut…
The inner crust of a mature neutron star is composed of an elastic lattice of neutron-rich nuclei penetrated by free neutrons. These neutrons can flow relative to the crust once the star cools below the superfluid transition temperature. In order to model the dynamics of this system, which is relevant for a range of problems from pulsar glitches to magnetar seismology and continuous gravitational-wave emission from rotating deformed neutron stars, we need to understand general relativistic Lagrangian perturbation theory for elastic matter coupled to a superfluid component. This paper develops …
Neutron stars are known to show accelerated spin-up of their rotational frequency called a glitch. Highly magnetized rotating neutron stars (pulsars) are frequently observed by radio telescopes (and in other frequencies), where the glitch is observed as irregular arrival times of pulses which are otherwise very regular. A glitch in an isolated neutron star can excite the fundamental (f)-mode oscillations which can lead to gravitational wave generation. Electromagnetic observations of pulsars (and hence pulsar glitches) require the pulsar to be oriented so that the jet is pointed toward the det…
We study analytic core-envelope models obtained in Negi et al. (1989) under slow rotation. We have regarded in the present study, the lower bound on the estimate of moment of inertia of the Crab pulsar, $I_{\rm Crab,45} \geq 2$ (where $I_{45}=I/10^{45}\rm g{cm}^2$) obtained by Gunn and Ostriker (1969) as a round off value of the recently estimated value of $I_{\rm Crab,45} \geq 1.93$ (Bejger \& Haensel 2003) for the Crab pulsar. If this value of lower bound is combined with the other observational constraint obtained for the Crab pulsar (Crawford \& Demiansky 2003), $G_h = I_{\rm core}/I_{\rm …
