ASCA observations of galactic jet systems

Recent studies with ASCA have shown very complicated, strange iron K features in the spectra of galactic jet systems. SS 433, the “classic” jet, was found to have pairs of Doppler-shifted lines, contrary to the previous belief that the receding X-ray jet is short and hidden behind the accretion disk. The transient jets, GRS 1915+105 and GRO J1655−40, show spectral dips, which have never been observed in any other source and are interpreted as absorption lines or Doppler-shifted absorption edges. If they are resonant absorption lines of helium-like iron, they would be the evidence of highly ionized, anisotropically distributed plasma near the jet engine. These features peculiar to galactic jet systems are expected to be explained in terms of the nature of the sources and the jet-formation mechanisms. Since ASCA was proved to be an excellent tool for diagnostics of jets, observation campaigns of the jet systems were planned and performed. SS 433 was observed about thirty times in the three years of the camp...