The double pulsar system J0737-3039: Modulation of a by B at eclipse

We have investigated the eclipse of the 23 ms pulsar, PSR J07373039A, by its 2.8 s companion PSR J07373039B in the recently discovered double pulsar system using data taken with the Green Bank Telescope at 820 MHz. We find that the pulsed flux density at eclipse is strongly modulated with the periodicity of the 2.8 s pulsar. The eclipse occurs earlier and is deeper at those rotational phases of B when its magnetic axis is aligned with the line of sight than at phases when its magnetic axis is at right angles to the line of sight. This is consistent with the eclipse of A being due to synchrotron absorption by the shock-heated plasma surrounding B, the asymmetry arising from the higher plasma densities expected in the B magnetosphere’s polar cusps. Subject headings: binaries: general — pulsars: general — pulsars: individual (PSR J07373039A, PSR J07373039B)