We discuss three different ways to arrive at kaon condensation at nc ≃ 3n0 where n0 is nuclear matter density: (1) Fluctuating around the n = 0 vacuum in chiral perturbation theory, (2) fluctuating around nVM near the chiral restoration density nχ where the vector manifestation of hidden local symmetry is reached and (3) fluctuating around the Fermi liquid fixed point at ∼ n0. They all share on...

We calculate the first dynamical evolutions of merging black hole-neutron star binaries that construct the combined black hole-neutron star spacetime in a general relativistic framework. We treat the metric in the conformal flatness approximation, and assume that the black hole mass is sufficiently large compared to that of the neutron star so that the black hole remains fixed in space. Using a...

The collapse of a massive star’s core, followed by a neutrino-driven, asymmetric supernova explosion, can naturally lead to pulsar recoils and neutron star kicks. Here, we present a two-dimensional, radiationhydrodynamic simulation in which core collapse leads to significant acceleration of a fully formed, nascent neutron star via an induced, neutrino-driven explosion. During the explosion, an ...

After more than a decade of actively accreting at about a tenth of the Eddington critical mass accretion rate, the neutron-star X-ray transient KS 1731–260 returned to quiescence in early 2001. We present a Chandra/ACIS-S observation taken several months after this transition. We detected the source at an unabsorbed flux of ∼ 2 × 10 erg cm s (0.5–10 keV). For a distance of 7 kpc, this results i...

We study the viscous effects on the interaction between the coplanar Be-star disc and the neutron star in Be/X-ray binaries, using a three-dimensional, smoothed particle hydrodynamics code. For simplicity, we assume the Be disc to be isothermal at the temperature of half the stellar effective temperature. In order to mimic the gas ejection process from the Be star, we inject particles with the ...

The accretion induced neutron star magnetic field evolution is studied through considering the accretion flow to drag the field lines aside and dilute the polar field strength, and as a result the equatorial field strength increases, which is buried inside the crust on account of the accretion induced global compression of star crust. The main conclusions of model are as follows: (i) the polar ...

We review current state of neutron star cooling theory and discuss the prospects to constrain the equation of state, neutrino emission and superfluid properties of neutron star cores by comparing the cooling theory with observations of thermal radiation from isolated neutron stars.

Recent observations suggest that neutron stars in low-mass X-ray binaries rotate within a narrow range of spin frequencies clustered around 300Hz. A proposed explanation for this remarkable fact is that gravitational radiation from a steady-state r-mode oscillation in the neutron star’s core halts the spin-up due to accretion. For the neutron star transients, balancing the time-averaged accreti...

Neutron star mass and radius measurements are becoming sufficiently accurate as to offer astrophysical constraints on the properties of neutron-rich matter near the nuclear saturation density. Current observations, which imply that the radius of a 1.4 solar mass neutron star lies between 10.4 and 12.9 km (95% confidence), also imply that 43 < L < 67 MeV, where L is a parameter describing the sl...