Models of jet production in black hole systems suggest that the properties of the accretion disk – such as its mass accretion rate , inner radius , and emergent magnetic field – should drive and modulate the production of relativistic jets .
Stellar-mass black holes in the ‘ ‘ low/hard ’ ’ state are an excellent laboratory in which to study disk–jet connections , but few coordinated observations are made using spectrometers that can incisively probe the inner disk .
We report on a series of 20 Suzaku observations of Cygnus X-1 made in the jet-producing low/hard state .
Contemporaneous radio monitoring was done using the Arcminute MicroKelvin Array radio telescope .
Two important and simple results are obtained : ( 1 ) the jet ( as traced by radio flux ) does not appear to be modulated by changes in the inner radius of the accretion disk ; and ( 2 ) the jet is sensitive to disk properties , including its flux , temperature , and ionization .
Some more complex results may reveal aspects of a coupled disk–corona–jet system .
A positive correlation between the reflected X-ray flux and radio flux may represent specific support for a plasma ejection model of the corona , wherein the base of a jet produces hard X-ray emission .
Within the framework of the plasma ejection model , the spectra suggest a jet base with v / c \simeq 0.3 , or the escape velocity for a vertical height of z \simeq 20 ~ { } GM / c ^ { 2 } above the black hole .
The detailed results of X-ray disk continuum and reflection modeling also suggest a height of z \simeq 20 ~ { } GM / c ^ { 2 } for hard X-ray production above a black hole , with a spin in the range 0.6 \leq a \leq 0.99 .
This height agrees with X-ray time lags recently found in Cygnus X-1 .
The overall picture that emerges from this study is broadly consistent with some jet–focused models for black hole spectral energy distributions in which a relativistic plasma is accelerated at z = 10–100 GM / c ^ { 2 } .
We discuss these results in the context of disk–jet connections across the black hole mass scale .