Outbursts in symmetric sources: The case of the galactic Jet GRS1915+105

We present a model to study outbursts in symmetric sources. The model fits the observed flux ratio evolution of the components and generates estimates of the geometric (component sizes, opening angles, system orientation with respect to the observer) and the kinematic (components speed, expansion velocities) properties of the system. We have applied the model to the prominent March 1994 radio flare in the galactic source GRS1915+105. We have found an asymmetry between the approaching and receding jets, which implies a slower expansion velocity of the receding component and may account for the slower steepening of its spectrum required to fit our model.