GRS 1915+105: The flux ratio of twin radio clouds as a measure of asymmetry between counter jets

Resolution of both approaching and receding ejecta in the galactic microquasars makes it possible to measure the flux ratio S-a/S-r of twin ejecta, which contains important information about the nature of the jets. We show that the flux ratio S-a/S-r = 8 +/- 1 observed from GRS 1915 + 105 during the prominent 1994 March/April radio flare can be explained in terms of relativistic motion of discrete radio clouds, if one assumes that the twin ejecta are similar but not completely identical, i.e., allowing for some asymmetry between the plasmoids in their speeds of propagation and/or luminosities. The recoil momentum due to asymmetrical ejection of the pair of plasmoids may be comparable to the momentum accumulated in the inner accretion disk. We suggest a possible explanation for the observed anticorrelation between the X-ray and radio flares; it may be the result of drastic structural changes in the inner disk caused by production of powerful jets. The delay between the times of decline of Xrays and the appearance of strong radio flares is explained by the time needed for expansion of radio clouds to become optically thin.