Related papers: Particle Probes with Superradiant Pulsars
Pulsars are among the most mysterious astrophysical objects in the Universe and are believed to be rotating neutron stars formed in supernova explosions. They are unique testing grounds of dense matter theories and gravitational physics and…
The recent discovery of burst oscillation at 1122Hz in the X-ray transient XTE J1739-285 supports the suggestion that it contains a submillisecond pulsar. In our estimations of the enormous dissipation effect in the transition boundary…
Giant radio pulses of the millisecond pulsar B1937+21 were recorded with the S2 VLBI system at 1.65 GHz with NASA/JPL's 70-m radio telescope at Tidbinbilla, Australia. These pulses have been observed as strong as 65000 Jy with widths <= 15…
We shall examine various types of equations of state for neutron stars, which determine the structure of neutron stars. In particular, the relation between mass and radius of neutron stars is of primary consideration. By combining an…
Pulsars are wonderful gravitational probes. Their tiny size and stellar mass give their rotation periods a stablility comparable to that of atomic frequency standards. This is especially true of the rapidly rotating "millisecond pulsars"…
The existence of neutron stars with $2M_\odot$ requires the strong stiffness of the equation of state (EoS) of neutron-star matter. We introduce a multi-pomeron exchange potential (MPP) working universally among 3- and 4-baryons to stiffen…
By directly inverting several neutron star observables in the three-dimensional parameter space for the Equation of State of super-dense neutron-rich nuclear matter, we show that the lower radius limit for PSR J0740+6620 of mass $2.08\pm…
We present the set of deep Neutron Star Interior Composition Explorer (NICER) X-ray timing observations of the nearby rotation-powered millisecond pulsars PSRs J0437-4715, J0030+0451, J1231-1411, and J2124-3358, selected as targets for…
We investigated recent observation data of pulsar masses of PSR J0740$+$6620, PSR J0348$+$0432, and PSR J1614$-$2230 based on the extended $\sigma$-$\omega$ model. We assumed that these pulsars are maximal mass compact star, which suggest…
Quasi-periodic X-ray brightness oscillations (QPOs) with frequencies around a kilohertz have now been discovered in more than a dozen neutron stars in low-mass X-ray binary systems using the Rossi X-ray Timing Explorer. There is strong…
Pulsar timing has enabled some of the strongest tests of fundamental physics. Central to the technique is the assumption that the detected radio pulses can be used to accurately measure the rotation of the pulsar. Here we report on a…
The behaviour of the pulsar spectrum at high radio frequencies can provide decisive information about the nature of the radio emission mechanism. We report recent observations of a selected sample of pulsars at lambda=9mm (32 GHz) with the…
(Abridged) The recent measurement of the mass of two $2\, M_\odot$ pulsars has raised the question whether such large masses allow for the existence of exotic degrees of freedom, such as hyperons, inside neutron stars. In the present work…
Equilibrium sequences were developed for rotating NS in the relativistic mean-field interaction framework using four density-dependent equations of state for the NS matter. These sequences were constructed for the observed rotation…
We have detected pulsed X-ray emission from the fastest millisecond pulsar known, PSR B1937+21 (P=1.558 msec), with ASCA. The pulsar is detected as a point source above $\sim 1.7$ keV, with no indication of nebulosity. The source flux in…
We analyze PSR J0952-0607, the most massive and fastest spinning neutron star observed to date, to refine constraints on the neutron star equation of state (EoS) and investigate its robustness against r-mode instabilities. With a mass of \(…
We report on new orbit-minimum photometry and revised radial-velocity fitting that provide an improved measurement of the mass of the neutron star (NS) in pulsar PSR~J0952$-$0607 at $M_NS = 2.35\pm 0.11 M_\odot$. With its fast spin and…
Gravitational redshifts of neutron stars have a theoretical upper limit of z=0.62. Also, it is generally believed that neutron stars have magnetic fields on the order of ten to the twelfth to ten to the thirteenth G. A previously predicted…
We construct equilibrium configurations of uniformly rotating neutron stars for selected relativistic mean-field nuclear matter equations of state (EOS). We compute in particular the gravitational mass ($M$), equatorial ($R_{\rm eq}$) and…
The moment of inertia of the pulsar A in the neutron star binary J0737-3039 will soon be measurable through detailed measurements of the periastron advance. We present the calculation of the moment of inertia of neutron stars with the…