SUPERORBITAL MODULATION OF X-RAY EMISSION FROM GAMMA-RAY BINARY LSI +61 303

M. Chernyakova, A. Neronov, S. Molkov, D. Malyshev, A. Lutovinov, G. Pooley
2012 Astrophysical Journal Letters  
We report the discovery of a systematic constant time lag between the X-ray and radio flares of the gamma-ray binary LSI +61 303, persistent over long, multi-year, time scale. Using the data of monitoring of the system by RXTE we show that the orbital phase of X-ray flares from the source varies from ϕ_X≃ 0.35 to ϕ_X≃ 0.75 on the superorbital 4.6 yr time scale. Simultaneous radio observations show that periodic radio flares always lag the X-ray flare by Δϕ_X-R≃ 0.2. We propose that the constant
more » ... phase lag corresponds to the time of flight of the high-energy particle filled plasma blobs from inside the binary to the radio emission region at the distance 10 times the binary separation distance. We put forward a hypothesis that the X-ray bursts correspond to the moments of formation of plasma blobs inside the binary system.
doi:10.1088/2041-8205/747/2/l29 fatcat:uwpamr3qivcinasnleemk2o3fm