The Role of Microquasars in Astroparticle Physics

I present an overview of past, present and future research on micro-quasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena and as-troparticle physics. After reminding the analogy with quasars, I focus on one of the best microquasar representatives, probably the archetype, namely GRS 1915+105, and present accretion and ejection phenomena , showing that only a multi-wavelength approach allows a better understanding of phenomena occurring in these sources. Thereafter, I review jets at different scales: compact jets, large-scale jets, and the interactions between ejection and the surrounding medium. I finish this review by showing that microquasars are good candidates to be emitters of astroparticles: very high energy photons, cosmic rays and neutrinos. 1 The pre-microquasar era: SS 433 In 1979 was discovered the microquasar prototype: SS 433, a high-energy source exhibiting precessing jets at frame velocity 0.26c, with emission lines observed in the optical, showing that the jet content was baryonic (Margon, 1984). SS 433 is surrounded by a supernova remnant: W50, and there are clear signs of interaction between SS 433 jets and W50 nebula (see 1