Relativistic outflows from X-ray binaries (a.k.a. `Microquasars')

Abstract

In this review I summarise the observational connections between accretion and relativistic outflows -- jets -- in X-ray binaries. I argue that jets are likely to be a fairly ubiquitous property of X-ray binaries as a whole, an assertion which can be tested by further observations of the Atoll-type X-ray binaries. I discuss broad patterns that are emerging from these observational studies, such as a correlation between `hard' X-ray states and the presence of radio emission, and the related anti-correlation between jet strength and mass-accretion rate as inferred from X-ray studies alone. I briefly discuss possible future directions for research and compare X-ray binary jets to those from Active Galactic Nuclei and Gamma Ray Bursts.

To appear in "Relativistic flows in Astrophysics", Springer Verlag Lecture Notes in Physics, Eds A.W. Guthmann, M. Georganopoulos, K. Manolakou and A. Marcowith