Conditions for jet formation in accreting neutron stars: the magnetic field decay

Accreting neutron stars can produce jets only if they are weakly magnetized (B similar to 10(8) G). On the other hand, neutron stars are compact objects born with strong surface magnetic fields (B similar to 10(12) C). In this work we study the conditions for jet formation in a binary system formed by a neutron star and a. massive donor star once the magnetic field has decayed due to accretion. We solve the induction equation for the magnetic field diffusion in a realistic neutron star crust and discuss the possibility of jet launching in systems like the recently detected Supergiant Fast X-ray Transients.