Recent Constraints on Jet physics and Properties Obtained from High Energy Observations of Microquasars

Abstract

The recent detections of microquasars at energies above a few hundred keV up to the TeV in one case has stimulated a strong interest and raised several questions. How are the MeV, GeV, and even TeV emissions, produced? What are the emission processes and in-fine the physics and media at the origin of the broad band spectra? What is the content of these media, and how are they powered? These sources are machines accelerating particles and matter to very high speed in collimated jets. While these are now known for more than twenty years (mainly with radio observations) and their behavior known to be tied to the accretion processes onto the compact object (studied via X-ray observations), their potential influence at high energy is just being recognized. In this review I will present a selection of recent results obtained with XMM-Newton, INTEGRAL, Fermi on 4U 1630$-$40, Cygnus X-1, and V404 Cygni and will discuss the possible interpretations of these results.