Energy and time-lag spectra of black-hole systems in the low state

Pablo Reig; Nikolaos D. Kylafis; Dimitris Giannios

doi:10.1051/0004-6361:20030449

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Energy and time-lag spectra of black-hole systems in the low state

Pablo Reig·Nikolaos D. Kylafis·Dimitris Giannios

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Abstract

Most, probably all, accreting binaries that are believed to contain a black-hole emit radio waves when they are in the low/hard state. Whenever this radio emission has been resolved, a jet-like structure has become apparent. We propose that Compton upscattering of low-energy photons in the jet can explain both the energy spectra and the time lags versus Fourier frequency observed in the low/hard state of black-hole systems. The soft photons originate in the inner part of the accretion disk. We have performed Monte Carlo simulations of Compton upscattering in a jet and have found that for a rather wide range of values of the parameters we can obtain power-law high-energy X-ray spectra with photon-number index in the range 1.5 - 2 and power-law time lags versus Fourier frequency with index ~ 0.7. The black-hole source Cyg X-1 in the low/hard state is well described by our model.

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Pablo Reig, Nikolaos D. Kylafis, Dimitris Giannios. 2003-03-26. Energy and time-lag spectra of black-hole systems in the low state. https://doi.org/10.1051/0004-6361%3A20030449

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