Jets from X-ray Binaries to Active Galactic Nuclei

Abstract

It is generally believed that active galactic nuclei (AGN) and black hole X-ray binaries (XRBs) have a similar central engine and that they could be described with a unified model. However, up to now such a model has not been fully established. In this thesis we present a symbiotic disk/jet model for both classes. Energy and mass conservation can be used to derive scaling laws for the emission of a jet. This allows us to identify the main parameters of the system: the mass of the central black hole and the accretion rate.<br /> We follow the idea that the spectral energy distributions (SEDs) of all weakly accreting black holes are probably jet dominated while highly accreting black holes are thermally dominated. Thus, the developedmodel can be used to argue for a unifying view of all weakly accreting black holes: a unification of XRBs and AGN. We classify the zoo of AGN in jet and disk dominated sources and test our unification schemeof weakly accreting sources by establishing a universal radio/X-ray correlation for XRBs and AGN.<br /> Our model is further tested by exploring the phenomenon of ultra-luminous X-ray sources (ULXs) which are bright off-nucleus X-ray point sources. If the central engine of XRBS and AGN is indeed similar, there should be a stellar analogue of a blazar (a blazar is an AGN with its relativistic jet pointing towards the observer). We show that these microblazars can indeed explain the known population of ULXs. As thedetection of a compact radio core at the positions of the ULX would strongly support this explanation, we have monitored a sample of ULXs to search for radio flares and continuous emission. We interpret the non-detections in the context of the universal radio/X-ray correlation.<br /> Finally we investigate if the complex timing behavior of accreting black holes is in agreement with ourjet model. The power law in the spectrum created by synchrotron emission originates mainly from one area in the jet. Thus, the power law in the SED can only vary in intensity and spectral index. Such a pivoting power law can be used to explain the Fourier time lags and other statistical properties of XRBs. Thus, our disk/jet model is in agreement with the observations and connects stellar mass XRBs to the supermassive AGN.