  We present a model for the radio outbursts of microquasars based on the
assumption of quasi-continuous jet ejection. The jets are `lit up' by shock
fronts traveling along the jets during outbursts. The observed comparatively
flat decay light curves combined with gradually steepening spectral slopes are
explained by a superposition of the radiation of the aging relativistic
particle population left behind by the shocks. This scenario is the low energy,
time-resolved equivalent to the internal shock model for GRBs. We show that
this model predicts energy contents of the radiating plasma similar to the
plasmon model. At the same time, the jet model relaxes the severe requirements
on the central source in terms of the rate at which this energy must be
supplied to the jet. Observations of `mini-bursts' with flat spectral slopes
and of infrared emission far from the source centre suggest two different
states of jet ejections: (i) A `mini-burst' mode with relatively stable jet
production and weak radio emission with flat spectra and (ii) an outburst mode
with strong variations in the jet bulk velocities coupled with strong radio
emission with steeper spectra. We also show that the continuous jets in
microquasars should terminate in strong shocks and possibly inflate radio lobes
similar to extragalactic jet sources. Finally, we investigate the possibility
of testing the predictions of this model with resolved radio observations.

Astrophysics