EDP Sciences
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Volume 441, Number 1, October I 2005
Page(s) 207 - 211
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20052832

A&A 441, 207-211 (2005)
DOI: 10.1051/0004-6361:20052832

Spin-up of the hyperon-softened accreting neutron stars

J. L. Zdunik, P. Haensel and M. Bejger

N. Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warszawa, Poland
    e-mail: [haensel;jlz;bejger]@camk.edu.pl

(Received 7 February 2005 / 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