| Abstract |
We discuss the dynamics of microquasar jets in the interstellar medium,
with specific focus on the effects of the X-ray binaries' space velocity
with respect to the local Galactic standard of rest. We argue that,
during late stages in the evolution of large scale radio nebulae around
microquasars, the ram pressure of the interstellar medium due to the
microquasar's space velocity becomes important, and that microquasars
with high velocities form the Galactic equivalent of extragalactic
head-tail sources, i.e., that they leave behind trails of stripped radio
plasma. Because of their higher space velocities, low-mass X-ray
binaries are more likely to leave trails than high-mass X-ray binaries.
We show that the volume of radio plasma released by microquasars over
the history of the Galaxy is comparable to the disk volume, and argue
that a fraction of a few percent of the radio plasma left behind by the
X-ray binary is likely mixed with the neutral phases of the ISM before
the plasma is removed from the disk by buoyancy. Because the formation
microquasars is an unavoidable by-product of star formation, and because
they can travel far from their birthplaces, their activity likely has
important consequences for the evolution of magnetic fields in forming
galaxies. We show that radio emission from the plasma inside the trail
should be detectable at low frequencies. We suggest that LMXBs with high
detected proper motions, such as XTE J1118+480, will be the best
candidates for such a search. |