Related papers: Pulsar Braking Index and Mass Accretion
Using the Rossi X-ray Timing Explorer (RossiXTE), astronomers have discovered that disk-accreting neutron stars with weak magnetic fields produce three distinct types of high-frequency X-ray oscillations. These oscillations are powered by…
The adiabatic index Gamma_1 for perturbations of dense matter is studied under various physical conditions which can prevail in neutron star cores. The dependence of Gamma_1 on the composition of matter (in particular, on the presence of…
The 6.7 GHz methanol maser emission, a tracer of forming massive stars, sometimes shows enigmatic periodic flux variations over several 10-100 days. In this Letter, we propose that this periodic variations could be explained by the…
We report the direct measurement of orbital period decay in the double neutron star pulsar system PSR B2127+11C in the globular cluster M15 at the rate of $(-3.95 \pm 0.13) \times 10^{-12}$, consistent with the prediction of general…
We summarize our current knowledge of neutron star masses and radii. Recent instrumentation and computational advances have resulted in a rapid increase in the discovery rate and precise timing of radio pulsars in binaries in the last few…
The long-term, highly periodic and correlated variations in both the pulse shape and the rate of slow-down of two isolated pulsars (PSRs) PSR B1828-11 and PSR B1642-03 were discovered recently. This phenomenon may provide evidence for "free…
We present a concise multimessenger inference of the neutron-star core sound-speed profile using GW170817 and three \textit{NICER} mass--radius posteriors (PSR J0030$+$0451, PSR J0740$+$6620, and PSR J0437$-$4715). The main result is not…
We carry out a general-relativistic global linear stability analysis of the amassed carbon fuel on the surface of an accreting neutron star to determine the conditions under which superbursts occur. We reproduce the general observational…
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…
The pulsar magnetic inclination angle is a key parameter for pulsar physics. It influences the observable properties of pulsars, such as the pulse beam width, braking index, polarisation, and emission geometry. In this study, we give a…
The pulsar J0537$-$6910 undergoes spin-up glitches more frequently than any other known pulsar, at a rate of roughly thrice per year. Its glitches are typically large and accompanied by spin-down rate changes $\Delta\dot\nu$ that partially…
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…
The observation of neutron stars enables the otherwise impossible study of fundamental physical processes. The timing of binary radio pulsars is particularly powerful, as it enables precise characterization of their (three-dimensional)…
This is an overview of pulsar accretion modeling. The physics of pulsar accretion, i.e., the process of plasma flow onto the neutron star surface, can be constrained from the spectral properties of the X-ray source. We discuss a new…
Some of radiopulsars have anomalous braking index values $n = \Omega \ddot{\Omega} / \dot{\Omega}^2 \sim \pm (10^3 \div 10^4) $. It is shown that such values may be related with nondipolar magnetic field. The precession of neutron star lead…
We present a detailed analysis of the Vela pulsar's rotational behaviour using approximately 100 months of observational data spanning from September 2016 to January 2025, during which four glitches were identified. Here, we demonstrate the…
As a result of observational difficulties, braking indices of only six rotation-powered pulsars are obtained with certainty, all of which are remarkably smaller than the value ($n=3$) expected for pure magnetodipole radiation model. This is…
A precise moment of inertia measurement for PSR J0737-3039A in the double pulsar system is expected within the next five years. We present here a new method of mapping the anticipated measurement of the moment of inertia directly into the…
If the causality condition [the speed of sound always remains less than that of light in vacuum, i. e., $v \leq c = 1$] is imposed on the spheres of homogeneous energy density, the `ratio of the specific heats', $\gamma \leq 2.59457$,…
Pulsars are known for their exceptionally stable rotation. However, this stability can be disrupted by glitches, sudden increases in rotation frequency whose cause is poorly understood. In this study, we present some preliminary results…