A jet model for Galactic black-hole X-ray sources: some constraining correlations
Abstract
Context: Some recent observational results impose significant constraints on all the models that have been proposed to explain the Galactic black-hole X-ray sources in the hard state. In particular, it has been found that during the hard state of Cyg X-1 the power-law photon number spectral index, Γ, is correlated with the average time lag, < t_lag>, between hard and soft X-rays. Furthermore, the peak frequencies of the four Lorentzians that fit the observed power spectra are correlated with both Γ and < t_lag>.
Aims: We have investigated whether our jet model can reproduce these correlations.
Methods: We performed Monte Carlo simulations of Compton upscattering of soft, accretion-disk photons in the jet and computed the time lag between hard and soft photons and the power-law index Γ of the resulting photon number spectra.
Results: We demonstrate that our jet model naturally explains the above correlations, with no additional requirements and no additional parameters.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2008
- DOI:
- 10.1051/0004-6361:20079159
- arXiv:
- arXiv:0807.2910
- Bibcode:
- 2008A&A...489..481K
- Keywords:
-
- radiation mechanisms: non-thermal;
- accretion;
- accretion disks;
- black hole physics;
- methods: statistical;
- X-rays: binaries;
- Astrophysics
- E-Print:
- doi:10.1051/0004-6361:20079159