IAR   05382
INSTITUTO ARGENTINO DE RADIOASTRONOMIA
Unidad Ejecutora - UE
artículos
Título:
High-energy emission from jet-clump interactions in microquasars
Autor/es:
ARAUDO, ANABELLA; BOSCH-RAMON, VALENTÍ; ROMERO, GUSTAVO E.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Año: 2009
ISSN:
0004-6361
Resumen:
High-mass microquasars are binary systems composed by a massive star and an accreting compact object from which relativistic jets are launched.   Considerable observational evidence supports the idea that winds of massive stars are clumpy. Individual clumps may interact with the jets in high-mass microquasars to produce outbursts of high-energy  emission. Gamma-ray flares have been detected in some high-mass X-raybinaries, such as Cygnus X-1, and likely in LS 5039 and LS I+61 303.We aim at predicting the high-energy emission produced by the interaction  between a jet and a clump of the stellar wind in a high-mass microquasar.Assuming a hydrodynamic scenario for the jet-clump interaction,we calculate the spectral energy distributions resulting fromthe dominant non-thermal processes: relativistic Bremsstrahlung, synchrotron and inverse Compton  radiation, for leptons, and proton-proton collisions, for hadrons.  Significant levels of emission in X-rays (synchrotron),high-energy gamma rays (inverse Compton), and very high-energy gamma rays (from the decay of neutral pions) are predicted, with luminosities in the different domains in the range ~ 10^32 - 10^35 erg/s. The spectral energy distributions strongly vary depending on the specific conditions.Jet-clump interactions could be detectable at high and very high energies. These phenomena may be behind the fast TeV variabilityfound in some high-mass X-ray binary systems. Our model can help to infer information on the properties of jets and clumpy winds through high-sensitivity gamma-ray astronomy.