Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-06-26
Astronomy and Astrophysics 375, 944-949 (2001)
Astronomy and Astrophysics
Astrophysics
6 pages, accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20010909
Observational appearance of a neutron star in the subsonic propeller state which is a companion of a wind-fed mass-exchange close binary system is discussed. During the subsonic propeller state the neutron star magnetosphere is surrounded by a spherical quasi-static plasma envelope, which is extended from the magnetospheric boundary up to the star accretion radius. The energy input to the envelope due to the propeller action by the neutron star exceeds the radiative losses and the plasma temperature in the envelope is of the order of the free-fall temperature. Under this condition the magnetospheric boundary is interchange stable. Nevertheless, I find that the rate of plasma penetration from the envelope into the magnetic field of the neutron star due to diffusion and magnetic field line reconnection processes is large enough for the accretion power to dominate the spindown power. I show that the accretion luminosity of the neutron star in the subsonic propeller state is 5*10**{30} - 10**{33} (dM/dt)_{15} erg/s, where dM/dt is the strength of the normal companion stellar wind which is parametrized in terms of the maximum possible mass accretion rate onto the neutron star magnetosphere. On this basis I suggest that neutron stars in the subsonic propeller state are expected to be observed as low luminous accretion-powered pulsars. The magnetospheric radius of the neutron star in this state is determined by the strength of the stellar wind, (dM/dt)_c, while the accretion luminosity is determined by the rate of plasma penetration into the star magnetosphere, (dM/dt)_a, which is (dM/dt)_a << (dM/dt)_c. That is why the classification of the neutron star state in these objects using the steady accretion model (i.e. setting (dM/dt)_a = (dM/dt)_c) can lead to a mistaken conclusion.
No associations
LandOfFree
On the state of low luminous accreting neutron stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the state of low luminous accreting neutron stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the state of low luminous accreting neutron stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-641552