An analysis of the broadband electromagnetic emission of the microquasar GX 339-4

The source GX 339-4 is an extensively studied galactic X-ray binary. Radio observations have revealed the presence of relativistic jets. In this work we present a jet model that provides good fits to a set of simultaneous radio and X-ray observations of GX 339-4. We assume that relativistic electrons and protons are present in the jets, and calculate both the leptonic and hadronic contributions to the radiation produced by several types of particle interac- tions. We also calculate the electromagnetic emission of secondary particles (pions, muons and electron-positron pairs) created in hadronic and electro- magnetic interactions, and assess the relevance of photon self-absorption in the jet. Finally, we estimate the pair production rate in order to investi- gate the possible connection between microquasars and the observed anti- matter annihilation line flux at 511 keV. Our predictions may be tested in the near future with data collected by the gamma-ray satellite Fermi and the Cherenkov telescope array HESS II.