Large-scale jets from black hole X-ray binaries

Black hole X-ray binaries (BH XRBs) can launch powerful outflows in the form of radio-emitting discrete jets, which are generally observed to be produced during bright outburst phases and to propagate up to parsec scales at relativistic speeds. However, little is known about the energy content, the powering mechanism or the composition of these jets, and studying them is also important for estimating the relevant feedback of BH XRBs on the surrounding environment. 
In this context, MeerKAT observations performed as part of the ThunderKAT LSP in the last 5 years have literally changed the game in the field, allowing us to detect a large number of new jets from these sources and to closely follow their evolution with our monitoring strategy. Thanks to the MeerKAT exceptional sensitivity and imaging capabilities at low (GHz) frequencies, the ejecta could be tracked all the way from launch to their point of deceleration in the interstellar medium, often through months or years of motion.
In this talk, I will show how monitoring these objects with MeerKAT has a high potential, as it allows us to model their dynamics and emission with great accuracy and, hence, to constrain their physical parameters. In the specific, I will show how, by applying models derived from gamma-ray burst physics to BH XRB jets, it is possible to obtain fundamental constraints on the jet kinetic energy, Lorentz factor, inclination angle and ejection date, as well as on the source environment. Overall, our results provide new insights into the physics of jets from BH XRBs and highlight the impact that MeerKAT observations are having in the field of accreting compact objects.