High-energy flares from jet-clump interactions

TL;DR

This paper models how interactions between stellar wind clumps and jets in high-mass microquasars produce high-energy flares, predicting observable X-ray and gamma-ray emissions and explaining rapid variability in certain binary systems.

Contribution

It introduces a detailed model of jet-clump interactions in high-mass microquasars, predicting high-energy emissions and variability, aiding understanding of jet and wind properties.

Findings

Predicted X-ray and gamma-ray luminosities up to 10^{34}-10^{35} erg/s.

Flares last about 1 hour, consistent with observed rapid variability.

Interactions could explain fast TeV variability in systems like Cygnus X-1.

Abstract

High-mass microquasars are binary systems composed by a massive star and a compact object from which relativistic jets are launched. Regarding the companion star, observational evidence supports the idea that winds of hot stars are formed by clumps. Then, these inhomogeneities may interact with the jets producing a flaring activity. In the present contribution we study the interaction between a jet and a clump of the stellar wind in a high-mass microquasar. This interaction produces a shock in the jet, where particles may be accelerated up to relativistic energies. We calculate the spectral energy distributions of the dominant non-thermal processes: synchrotron radiation, inverse Compton scattering, and proton-proton collisions. Significant levels of X- and gamma-ray emission are predicted, with luminosities in the different domains up to ~ 10^{34} - 10^{35} erg/s on a timescale of about ~ 1 h. Finally, jet-clump interactions in high-mass microquasars could be detectable at high energies. These phenomena may be behind the fast TeV variability found in some high-mass X-ray binary systems, such as Cygnus X-1, LS 5039 and LS I+61 303. In addition, our model can help to derive information on the properties of jets and clumpy winds.