ON THE X-RAY/TEV CONNECTION IN GALACTIC JET SOURCES

摘要

There are three Galactic jet sources from which TeV emission has been detected: LS 5039, LS I + 61 303 and Cygnus X-1. These three sources show power-law tails in X-rays and soft gamma-rays that could indicate a nonthermal origin of this radiation. In addition, all three sources apparently show correlated and complex behavior at X-ray and TeV energies. In some cases, this complex behavior is related to the orbital motion (e. g. LS 5039, LS I + 61 303), and in some others it is related to some transient events occurring in the system (e. g. Cygnus X-1, and likely also LS I + 61 303 and LS 5039). Based on modeling results or on energetic grounds, it seems difficult to explain the emission in the X-/soft gamma-ray and the TeV bands as coming from the same (i.e. one-zone) region. We also stress the importance of the pair creation phenomena in these systems, which harbor a massive and hot star, for the radio and the X-ray emission, as a secondary pair radiation component may be significant in these energy ranges. Finally, we point out that the presence of the star can indeed have a strong impact on both the nonthermal radiation production and the jet dynamics.