The cooling of neutron stars by URCA processes in the kaon-condensed neutron star matter for various forms of nuclear symmetry energy is investigated. The kaonnucleon interactions are described by a chiral lagrangian. Nuclear matter energy is parametrized in terms of the isoscalar contribution and the nuclear symmetry energy in the isovector sector. High density behaviour of nuclear symmetry en...

A young neutron star with large spin-down power is expected to be closely surrounded by an e pair plasma maintained by the conversion of γ-rays associated with the star’s polar-cap and/or outer-gap accelerators. Cyclotron-resonance scattering by the e and e within several radii of such neutron stars prevents direct observations of thermal X-rays from the stellar surface. Estimates are presented...

Formation of a neutron star is accompanied by neutrino emission carring about 10% of the rest energy of the star. Toroidal field produced by twisting of a dipole field in differentially rotating star is antisymmetric. Its summation with antisymmetric toroidal field results in braking of mirror symmetry of the magnetic field . For large magnetic field the neutron decay rate depends on its streng...

After almost 2.5 years of actively accreting, the neutron star X-ray transient and eclipsing binary MXB 1659–29 returned to quiescence in 2001 September. We report on a Chandra observation of this source taken a little over a month after this transition. The source was detected at an unabsorbed 0.5–10 keV flux of only (2.7 − 3.6) × 10 erg cm s, which implies a 0.5–10 keV X-ray luminosity of app...

The stages that follow the merging of two neutron stars are discussed. It is shown that if a rapidly rotating gravitationally bound object is formed after the merging (a spinar or a massive neutron star), then the characteristic time of its evolution is determined by a fundamental value tspin = 3k mpe 2h̄ mec 5/2G1/2 ≈ 10s · κ , where the dimensionless value κ = 100 ÷ 1000 depends on the exact e...

We present results of a population synthesis study aimed at examining the role of spin-kick alignment in producing a correlation between the spin period of the first-born neutron star and the orbital eccentricity of observed double neutron star binaries in the Galactic disk. We find spin-kick alignment to be compatible with the observed correlation, but not to alleviate the requirements for low...

The stages that follow the merging of two neutron stars are discussed. It is shown that if a rapidly rotating gravitationally bound object is formed after the merging (a spinar or a massive neutron star), then the characteristic time of its evolution is determined by a fundamental value tspin = κ m2pe 2h̄ mec 5/2G1/2 ≈ 7 · 10s · κ , where the dimensionless value κ depends on the exact equation o...

We investigate the possibility that mass transfer early in the evolution of a massive binary can effect a reversal of the end states of the two components, resulting in a neutron star which forms before a black hole. In this sense, such systems would comprise the high-mass analogues of white dwarf-neutron star systems such as PSR B2303+46. One consequence of this reversal is that a second episo...

A model of an accelerated expansion of the Crab Nebula powered by the spinning-down Crab pulsar is proposed, in which time dependence of the acceleration is connected with evolution of pulsar luminosity. Using recent observational data, we derive estimates of the Crab neutron-star moment of inertia. Correlations between the neutron star moment of inertia and its mass and radius allow for rough ...

Karl-Ludwig Kratz Universität Mainz Email: [email protected] An interesting question in nuclear astrophysics is the fate of post X-ray burst matter. Once an accreting neutron star has undergone thermonuclear runaway, the ashes of the burst are forced down into the crust of the neutron star. With increasing density a volume element of matter undergoes a number of electron captures and neutron...