Green Bank Telescope Observations of the Eclipse of Pulsar "A" in the Double Pulsar Binary PSR J0737-3039

We report on the first Green Bank Telescope observations at 427, 820 and 1400MHz of the newly discovered, highly inclined and relativistic double pulsarbinary. We focus on the brief eclipse of PSR J0737-3039A, the faster pulsar,when it passes behind PSR J0737-3039B. We measure a frequency-averaged eclipseduration of 26.6 +/- 0.6 s, or 0.00301 +/- 0.00008 in orbital phase. Theeclipse duration is found to be significantly dependent on radio frequency,with eclipses longer at lower frequencies. Specifically, eclipse duration iswell fit by a linear function having slope (-4.52 +/- 0.03) x 10^{-7}orbits/MHz. We also detect significant asymmetry in the eclipse. Eclipseingress takes 3.51 +/- 0.99 times longer than egress, independent of radiofrequency. Additionally, the eclipse lasts (40 +/- 7) x 10^{-5} in orbitalphase longer after conjunction, also independent of frequency. We detectsignificant emission from the pulsar on short time scales during eclipse insome orbits. We discuss these results in the context of a model in which theeclipsing material is a shock-heated plasma layer within the slower PSRJ0737-3039B's light cylinder, where the relativistic pressure of the fasterpulsar's wind confines the magnetosphere of the slower pulsar.Comment: 12 pages, 3 figure