Probing the Eclipse of J0737–3039A with Scintillation

We have examined the interstellar scintillations of the pulsars in the double-pulsar binary system. Near the time of the eclipse of pulsar A by the magnetosphere of B, the scintillations from both pulsars should be highly correlated because the radiation is passing through the same interstellar plasma. We report confirmation of this effect using 820 and 1400 MHz observations made with the Green Bank Telescope. The correlation allows us to constrain the projected relative position of the two pulsars at closest approach to be 4000 ± 2000 km, corresponding to an inclination that is only 0.°29 ± 0.°14 away from 90°. It also produces a two-dimensional map of the spatial correlation of the interstellar scintillation. This shows that the interstellar medium in the direction of the pulsars is significantly anisotropic. When this anisotropy is included in the orbital fitting, the transverse velocity of the center of mass is reduced from the previously published value of 141 ± 8.5 km s-1 to 66 ± 15 km s-1.