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The ``Reflection'' Effect

It seems at first glance that a binary system is not the most likely place for an ejecting NS to exist: the dense stellar wind absorbs coherent radiowaves and reduces the lifetime of the star at the ejection stage. This is indeed the case. However, there is another important factor which helps (from the point of view of observation) in distinguishing NS in a binary system from a single NS. It should be recalled that most (99.99 percent) of the energy is dissipated by single radiopulsars in the form of relativistic particles and low-frequency electromagnetic waves which are not observable. In the case of a binary system, however, the normal star may trap a considerable part of the relativistic wind ( tex2html_wrap_inline11353 , where tex2html_wrap_inline9378 is the radius of the normal star) and convert it into a form in which it can be detected on the Earth. This gives rise to an interesting analog of the classical reflection or heating effect (Lipunov, 1980[97]; Lipunov and Prokhorov, 1984[110]; Harding, 1991[64]; Lipunov and Nazin, 1994[119]). The main mechanisms of energy conversion are the synchrotron radiation of relativistic particles in the magnetic field of a normal star and nuclear transformation of ultrahigh-energy particles  colliding with the stellar wind matter of the same star.

The total power of the energy of relativistic particles transformed in this way is estimated from

equation3689

where tex2html_wrap_inline11357 is the characteristic size of the capture region expressed in units of the semi-major axis ( tex2html_wrap_inline11359 ). For close binary systems, tex2html_wrap_inline11361 -0.3 and the transformation coefficient may be several percent.

Apart from the reflection effect, transient  floating and bursting of caverns,  or the radioburster  phenomenon, may also be observed.

An ejector  in a pair with a normal star can appear as a new phenomenon - an induced radiopulsator. Synchrotron radioemission of relativistic particles captured by the magnetic field of the optical star must be strictly periodic in nature due to the rotation of a normal star (Lipunov and Nazin, 1993, 1994).[118, 119] The period of an induced radiopulsator may be confined in the interval of some hours to some days.


next up previous contents index
Next: Other Candidates for Ejecting Up: Ejectors in Massive Binary Previous: Why must a radiopulsar

Mike E. Prokhorov
Sat Feb 22 18:38:13 MSK 1997