On the Role of the Accretion Disk in Black Hole Disk-Jet Connections. (arXiv:1207.3752v1 [astro-ph.HE])

On the Role of the Accretion Disk in Black Hole Disk-Jet Connections. (arXiv:1207.3752v1 [astro-ph.HE]):
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 ~ 0.3, or the escape velocity for a vertical height of z ~ 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 ~ 20 GM/c^2 for hard X-ray
production above a black hole, with a spin in the range 0.6 < a < 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.