ar X iv : a st ro - p h / 99 03 48 8 v 1 3 1 M ar 1 99 9 Hydrodynamics of black hole – neutron star coalescence

ar X iv : a st ro - p h / 99 01 30 5 v 1 2 1 Ja n 19 99 Creation of a dense torus in the coalescence of a black hole with a neutron star

We used a newtonian SPH (smooth-particle hydrodynamics) code to follow the final stages of evolution of a coalescing binary system of a neutron star and a black hole. We find that the outcome of the “merger” is very sensitive to the equation of state describing the neutron star. A neutron star with a soft equation of state (polytrope with index Γ = 5/3) is completely disrupted, and a fairly lar...

ar X iv : a st ro - p h / 99 03 09 0 v 1 5 M ar 1 99 9 Origin of GRB Afterglows in the Model of Galactic Neutron Stars

The launch of the Beppo-Sax satellite gave a unique opportunity to investigate gamma ray bursts (GRB) in different spectral regions. The large diversity of the afterglow behavior creates additional problems for the cosmological model with a fireball. Formation of the afterglow giving the observed diversity of properties is suggested in the Galactic neutron star model of GRBs. It is based on the...

ar X iv : a st ro - p h / 98 08 21 9 v 1 2 0 A ug 1 99 8 Sgr A ∗ : A supermassive black hole or a spatially extended object ?

ar X iv : a st ro - p h / 98 10 37 9 v 1 2 3 O ct 1 99 8 Supermassive Black Holes Then and Now ∗

Recent surveys suggest that most or all normal galaxies host a massive black hole with 1/100 to 1/1000 of the visible mass of the spheroid of the galaxy. Various lines of argument suggest that these galaxies have merged at least once in our past lightcone, and that the black holes have also merged. This leads to a merger rate of massive black holes of about 1/yrs.

ar X iv : a st ro - p h / 99 03 18 6 v 1 1 1 M ar 1 99 9 Preprint USM - TH - 73 Neutrino Scattering Off Spin - Polarized Particles in Supernovae

We calculate neutrino and anti-neutrino scattering off electrons and nucleons in supernovae using a detailed Monte Carlo transport code incorporating realistic equations of state. The goal is to determine whether particles in a neutron star core, partially spin-aligned by the local magnetic field, can give rise to asymmetric neutrino emission via the standard parity breaking weak force. We conc...