On the X-ray/TeV connection in Galactic jet sources

TL;DR

This paper reviews the connection between X-ray and TeV gamma-ray emissions in Galactic jet sources, highlighting complex behaviors, modeling challenges, and the influence of stellar environments on jet dynamics and radiation.

Contribution

It provides a comprehensive analysis of the multi-wavelength behavior of Galactic jet sources and discusses the impact of stellar environments on emission mechanisms and jet dynamics.

Findings

TeV emission detected in three Galactic jet sources.

Complex correlated behaviors at X-ray and TeV energies observed.

Pair creation phenomena significantly affect radio and X-ray emissions.

Abstract

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 at X-rays and soft gamma-rays that could indicate a non-thermal origin for 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 event occurring in the system (e.g. Cygnus X-1, and likely also LS I +61 303 and LS 5039). Based on modeling or energetic grounds, it seems difficult to explain the emission in the X-/soft gamma-ray and the TeV bands as coming from the same region (i.e. one-zone). We also point out 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, since a secondary pair radiation component may be significant in these energy ranges. Finally, we discuss that in fact the presence of the star can indeed have strong impact on, beside the non-thermal radiation production, the jet dynamics.