Related papers: On the pulsar spin frequency derivatives and the g…
There are currently two well-accepted models that explain how pulsars exhibit glitches, sudden changes in their regular rotational spin-down. According to the starquake model, the glitch healing parameter, Q, which is measurable in some…
The timing properties of radio pulsars provide a unique probe of neutron star interiors. Recent observations have uncovered quasiperiodicities in the timing and pulse properties of some pulsars, a phenomenon that has often been attributed…
Pulsar glitches offer an insight into the dynamics of superfluids in the high density interior of a neutron star. To model these phenomena, however, one needs to have an understanding of the dynamics of a turbulent array of superfluid…
We investigate the impact of intrinsic, kinematic and gravitational effects on high precision pulsar timing. We present an analytical derivation and a numerical computation of the impact of these effects on the first and second derivative…
Many pulsars are observed to "glitch", i.e. show sudden jumps in their rotational frequency $\nu$, some of which can be as large as $\Delta \nu/\nu\approx 10^{-6}-10^{-5}$ in a subset of pulsars known as giant glitchers. Recently Pizzochero…
We present timing solutions from the Fermi-LAT observations of gamma-ray pulsars PSR J0835$-$4510 (Vela), PSR J1023$-$5746, PSR J2111$+$4606, and PSR J2229$+$6114. Data ranges for each pulsar extend over a decade. From data analysis we have…
A rotating superfluid forms an array of quantized vortex lines which determine its angular velocity. The spasmodic evolution of the array under the influence of deceleration, dissipation, and pinning forces is thought to be responsible for…
A large sample of pulsars was observed as part of the Meterwavelength Single-pulse Polarimetric Emission Survey. We carried out a detailed fluctuation spectral analysis which revealed periodic features in 46% pulsars including 22 pulsars…
Glitches -- sudden increases in spin rate -- are observed in many pulsars. One mechanism advanced to explain glitches in the youngest pulsars is that they are caused by a starquake, a sudden rearrangement of the crust of the neutron star.…
The recent massive measurements of pulsar frequency second derivatives have shown that they are 100-1000 times larger than expected for standard pulsar slowdown low. Moreover, the second derivatives as well as braking indices are even…
We investigate the chaotic spin-down behavior seen from some pulsars in terms of the nonlinear superfluid dynamics. To this end, we numerically solve the set of equations for the superfluid-normal matter system whose coupling is mediated by…
We report on a timing analysis of archival observations of the Anomalous X-ray Pulsar 1RXSJ170849.0-400910 made with the RXTE Proportional Counter Array. We detect a new large glitch (Delta nu / nu ~ 3 x 10^-6) which occurred between 2001…
PSR J0537-6910, also known as the Big Glitcher, is the most prolific glitching pulsar known, and its spin-induced pulsations are only detectable in X-ray. We present results from analysis of 2.7 years of NICER timing observations, from 2017…
The frequent glitches (sudden increases of the apparent angular velocity) observed in certain pulsars are generally believed to be attributable to discontinuous angular momentum transfer to the outer neutron star crust from a differentially…
Context: The Crab pulsar underwent its largest timing glitch on 2017 Nov 8. The event was discovered at radio wavelengths, and was followed at soft X-ray energies by observatories, such as XPNAV and NICER. aims: This work aims to compare…
Pulsars are known for their superb timing precision, although glitches can interrupt the regular timing behavior when the stars are young. These glitches are thought to be caused by interactions between normal and superfluid matter in the…
We study the pulsar timing properties and the data analysis methods during glitch recoveries. In some cases one first fits the time-of-arrivals (TOAs) to obtain the "time-averaged" frequency $\nu$ and its first derivative $\dot\nu$, and…
One large glitch was detected in PSR B1737$-$30 using data spanning from MJD 57999 to 58406 obtained with the newly built Shanghai Tian Ma Radio Telescope (TMRT). The glitch took place at the time around MJD 58232.4 when the pulsar…
We study statistical properties of stochastic variations in pulse arrival times, timing noise, in radio pulsars using a new analysis method applied in the time domain. The method proceeds in two steps. First, we subtract low-frequency…
Pulsars are spinning neutron stars which emit an electromagnetic beam. We expect pulsars to slowly decrease their rotational frequency. However, sudden increases of the rotational frequency have been observed from different pulsars. These…