Neutron star spin-kick velocity correlation effect on binary neutron star coalescence rates and spin-orbit misalignment of the components

We study the effect of the neutron star spin -- kick velocity alignment observed in young radio pulsars on the coalescence rate of binary neutron stars. Two scenarios of the neutron star formation are considered: when the kick is always present and when it is small or absent if a neutron star is formed in a binary system due to electron-capture degenerate core collapse. The effect is shown to be especially strong for large kick amplitudes and tight alignments, reducing the expected galactic rate of binary neutron star coalescences compared to calculations with randomly directed kicks. The spin-kick correlation also leads to a much narrower NS spin-orbit misalignment.Comment: 7 pages, 5 figures, accepted for publiction in MNRA

How is Binary Radio-Pulsars with Black Holes Population Rich?

Using "Scenario Machine" we have carried out population synthesis of radio pulsar with black hole binaries (BH+Psr) in context of the most wide assumptions about star mass loss during evolution, binary stars mass ratio distribution, kick velocity and envelope mass lost during collapse. Our purpose is to display that under any suppositional parameters of evolution scenario BH+Psr population have to be abundant in Galaxy. It is shown that in the all models including models evolved by Heger et al. (2002), Woosley et al. (2002), Heger et al. (2003) expected number of the black holes paired with radio pulsars is sufficient enough to discover such systems within the next few years.Comment: 8 pages, 4 figures, accepted to MNRA

Developing Effective Roll Cooling Systems Based on Computational Simulation

In order to retrofit a roll cooling system at the JSC ‘Katur Invest’ rolling mill, computational simulation was carried out for a process of accelerated emulsion spray cooling the rolls heated during rolling. Initial and boundary conditions for the Fourier equation in the case of a body of infinite length and arbitrary cross-sectional shape were determined for the thermal state conditions of rolls in mill stands No. 1, 2, 5, 7. After model adaptation, a comparative analysis of the roll temperature field dynamics in different cooling conditions was made based on experimental data. The analysis revealed that extending the time of emulsion cooling, evenwithout any further cooling process intensification, allows to significantly reduce both the maximum temperature level in a roll and its penetration depth, which results in required roll surface temperature reduction. Based on computational simulation, cooling parameters and conditions for the retrofitted cooling system are selected. Experimental data on roll surface temperature as measured before and after retrofitting the cooling system proved its effectiveness. Keywords: rolling, rolls, accelerated cooling, temperature field, simulatio

Luminosity function of binary X-ray sources calculated using the Scenario Machine

Using the ``Scenario Machine'' we have carried out a population synthesis of X-ray binaries for the purpose of modelling of X-ray luminosity functions (XLFs) in different types of galaxies: star burst, spiral, and elliptical. This computer code allows to calculate, by using Monte Carlo simulations, the evolution of a large ensemble of binary systems, with proper accounting for the spin evolution of magnetized neutron stars. We show that the XLF has no universal type. It depends on the star formation rate in the galaxy. Also it is of importance to take into account the evolution of binary systems and life times of X-ray stages in theoretical models of such functions. We have calculated cumulative and differential XLFs for the galaxy with the constant star formation rate. Also we have calculated cumulative luminosity functions for different intervals of time after the star formation burst in the galaxy and curves depicting the evolution of the X-ray luminosity after the star formation burst in the galaxy.Comment: 22 pages, 13 figure