Related papers: Glitches, torque evolution and the dynamics of you…
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…
Synchrotron radiation of ultra-relativistic particles accelerated in a pulsar wind nebula may dominate its spectrum up to gamma-ray energies. Because of the short cooling time of the gamma-ray emitting electrons, the gamma-ray emission zone…
A quake model of bare strange stars for normal pulsar glitches is summarized. Three mechanisms being responsible for developing elastic stress energy are presented. It is suggested that other kinds of glitches (e.g, the frequency glitch in…
The stability of the optical pulse of the Crab pulsar is analyzed based on the 1 $\mu$s resolution observations with the Russian 6-meter and William Hershel telescopes equipped with different photon-counting detectors. The search for the…
Almost all pulsars with anomalous positive $\ddot \Omega $ measurements (corresponding to anomalous braking indices in the range 5$<n<$100), including all the pulsars with observed large glitches ($\Delta\Omega/\Omega$ $>$ 10$^{-7}$) as…
The spin-down law of pulsars is generally perturbed by two types of timing irregularities: glitches and timing noise. Glitches are sudden changes in the rotational frequency of pulsars, while timing noise is a discernible stochastic…
$\sim 6\%$ of all known pulsars have been observed to exhibit sudden spin-up events, known as glitches. For more than fifty years, these phenomena have played an important role in helping to understand pulsar (astro)physics. Based on the…
Glitches are sudden increases in the rotation rate $\nu$ of neutron stars, which are thought to be driven by the neutron superfluid inside the star. The Vela pulsar presents a comparatively high rate of glitches, with 21 events reported…
Based on the magnetic dipole radiation from the 3P2 neutron superfluid vortices (3P2NSFV) in neutron stars, we propose a model of glitch for young pulsars by oscillation between B phase and A phase of 3P2 Neutron superfluid. The main…
Pulsars are highly magnetized rotating neutron stars with a very stable rotation speed. Irrespective of their stable rotation rate, many pulsars have been observed with the sudden jump in the rotation rate, which is known as pulsar glitch.…
A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation which is emitted by returning positrons moving toward the surface of the neutron star along field lines of the inclined magnetic…
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…
A glitch is a rare and sudden increase in the otherwise steadily decreasing rotation rate of a pulsar. Its cause is widely attributed to the transfer of angular momentum to the crust of the star from the array of superfluid vortices…
A Fourier transform analysis of 2.5 million spectra in the SDSS survey was carried out to detect periodic modulations contained in their intensity versus frequency spectrum. A statistically significant signal was found for 223 galaxies…
Glitches are commonly observed for pulsars, which are explained by various mechanisms. One hypothesis attributes the glitch effect to the instantaneous moment of inertia change of the whole star caused by a starquake, which is similar to…
A newly born millisecond magnetar is thought to be the central engine of some gamma-ray bursts (GRBs), especially those that present long-lasting X-ray plateau emissions. By solving the field equations, we find that when the rotational…
Pulsars are spinning extremely rapidly with periods as short as about $1.4$ milliseconds and delays of a few milliseconds per year at most, thus providing the most accurate clocks in the Universe. Nevertheless, sudden spin ups have been…
Pulsars are rotating neutron stars, sweeping the emission regions from the magnetic poles across our line of sight. Isolated neutron stars lose angular momentum through dipole radiation and (possibly) particle winds, hence they slow down…
We investigate the evolution of pulsars in the (P,P-dot) diagram. We first present analytical formulae to follow the evolution of a pulsar using simple exponential models for magnetic field decay and alignment. We then compare these…
A statistical scenario is proposed to explain the $\gamma$-ray variability and flares of the Crab nebula, which were observed recently by the Fermi/LAT. In this scenario electrons are accelerated in a series of knots, whose sizes follow a…