A study of the light bending phenomenon under full general relativity for a pulsar in a binary with a Schwarzschild black hole

The values of the bending delays in the signal of a radio pulsar in a binary with a stellar mass black hole as a companion have been calculated accurately within a full general relativistic framework considering the Schwarzchid spacetime near the companion. The results match with the pre-existing approximate analytical expressions unless both of the orbital inclination angle and the orbital phase are close to 90 & DEG;. For such a case, the approximate analytical expressions underestimate the value of the bending delay. On the other hand, for systems like the double pulsar, those expressions are valid throughout the orbital phase, unless its inclination angle is very close to 90 & DEG;. For a pulsar-black hole binary, the bending phenomenon also increases the strength of the pulse profile and sometimes can lead to a small low intensity tail.

Automated summary

The accurate calculation of bending delays in the signal of a radio pulsar in a binary system with a stellar mass black hole as a companion has been performed. The results match with the pre-existing approximate analytical expressions, except when both the orbital inclination angle and the orbital phase are close to 90 degrees. For systems like the double pulsar, the approximate analytical expressions are valid throughout the orbital phase, unless the inclination angle is very close to 90 degrees. In a pulsar-black hole binary, the bending phenomenon also increases the strength of the pulse profile and can sometimes lead to a small low intensity tail.