Spin-up of the hyperon-softened accreting neutron stars
N. Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warszawa, Poland e-mail: [haensel;jlz;bejger]@camk.edu.pl
Accepted: 25 April 2005
We study the spin-up of the accreting neutron stars with a realistic hyperon-softened equation of state. Using precise 2D calculations we study the evolutionary tracks of accreting neutron stars in the angular-momentum – frequency planes. In contrast to the case of spinning-down solitary radio-pulsars, where a strong back-bending behavior has been observed, we do not see back-bending phenomena in the accretion-powered spinning-up case. We conclude that in the case of accretion-driven spin-up the back-bending is strongly suppressed by the mass-increase effect accompanying the angular-momentum increase.
Key words: dense matter / equation of state / stars: neutron / stars: binaries: general
© ESO, 2005