Related Astro2010 Whitepapers: " Extreme Astrophysics with Neutron Stars " (D. Lai et al.) " Gravitational Wave Detection Using Pulsars " (P. Demorest et al.) " X-Ray Timing of Neutron Stars, Astrophysical Probes of Extreme Physics " (Z. Arzoumanian et al.)

Neutron stars with extremely high central energy density are natural laboratories to investigate the appearance and the properties of compactified extra dimensions with small compactification radius, if they exist. Using the same formalism, these exotic hybrid stars can be described as neutron stars with quark core, where the high energy density allows the presence of heavy quarks (c, b, t). We...

The thermal, spin and magnetic evolution of neutron stars in the old low mass binaries is first explored. Recycled to very short periods via accretion torques, the neutron stars lose their magnetism progressively. If accretion proceeds undisturbed for 100 Myrs these stars can rotate close to break up with periods far below the minimum observed of 1.558 ms. We investigate their histories using p...

Using the StarTrack population synthesis code we analyze the formation channels possibly available to double neutron star binaries and find that they can be richer than previously thought. We identify a group of short lived, tight binaries, which do not live long enough to escape their host galaxies, despite their large center-of-mass velocities. We present our most recent results on all possib...

The minimal cooling paradigm for neutron star cooling assumes that enhanced cooling due to neutrino emission from any direct Urca process, due either to nucleons or to exotica such as hyperons, Bose condensates, or deconfined quarks, does not occur. This scenario was developed to replace and extend the so-called standard cooling scenario to include neutrino emission from the Cooper pair breakin...

Pulsars have been recognized as normal neutron stars, but sometimes argued as quark stars. Sub-millisecond pulsars, if detected, would play an essential and important role in distinguishing quark stars from neutron stars. We focus on the formation of such sub-millisecond pulsars in this paper. A new approach to form a sub-millisecond pulsar (quark star) via accretion induced collapse (AIC) of a...

We review a current state of cooling theory of isolated neutron stars. The main regulators of neutron star cooling are discussed. We outline the sensitivity of cooling models to equation of state of matter in the neutron star core; the presence or absence of enhanced neutrino emission; superfluidity of baryonic component of matter. A comparison of the cooling theory with observations of thermal...

The effects of core deformation and of its dynamical reorientation and rotational excitation on the inclusive single-neutron knockout reaction cross sections on light spherical target nuclei are examined. The projectile nuclei are modeled within the framework of a weak-coupling, quadrupole-deformed core-plus-neutron two-body model. We formulate the inclusion of this non-spectator-core degree of...

We study the spin-parity distribution P(J,E) of Gd excited states above the neutron separation energy that are expected to be populated via the neutron pickup reaction Gd(He,He)Gd. In general, modeling of the spin-parity distribution is important for the applicability of the surrogate reaction technique as a method of deducing reaction cross sections. We model excited states in Gd as rotational...

We study the properties of neutron stars adopting relativistic equations of state of neutron star matter, calculated in the framework of the relativistic Brueckner–Hartree–Fock approximation for electrically charge neutral neutron star matter in beta–equilibrium. For higher densities more baryons (hyperons etc.) are included by means of the relativistic Hartree– or Hartree–Fock approximation. T...