Evolution of magnetic field and spin period in accreting neutron stars

نویسنده

  • K. S. Cheng
چکیده

Based on the accretion-induced magnetic field decay model, in which a frozen field and an incompressible fluid are assumed, we obtain the following results: (1) an analytic relation between the magnetic field and spin period, if the fastness parameter of the accretion disk is neglected (The evolutionary tracks of accreting neutron stars in the P-B diagram in our model are different from the equilibrium period lines when the influence of the fastness parameter is taken into account.); (2) the theoretical minimum spin period of an accreting neutron star ismax(1.1ms ( ∆M M )−1R−5/14 6 I45( M M )−1/2 , 1.1ms ( M M )−1/2 R 17/14 6 ), independent of the accretion rate (X-ray luminosity) but dependent on the total accretion mass, ∆M ; however, the minimum magnetic field depends on the accretion rate; (3) the magnetic field strength decreases faster with time than does the period.

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تاریخ انتشار 2000