A Jet Source of Event Horizon Telescope Correlated Flux in M87
  Event Horizon Telescope (EHT) observations at 230 GHz are combined with Very
Long Baseline Interferometry (VLBI) observations at 86 GHz and high resolution
Hubble Space Telescope optical observations in order to constrain the broadband
spectrum of the emission from the base of the jet in M87. The recent VLBI
observations of Hada et al provide much stricter limits on the 86 GHz
luminosity and component acceleration in the jet base than was available to
previous modelers. They reveal an almost hollow jet on sub-mas scales. Thus,
tubular models of the jet base emanating from the innermost accretion disk are
considered within the region responsible for the EHT correlated flux. There is
substantial synchrotron self absorbed opacity at 86 GHz. A parametric analysis
indicates that the jet dimensions and power depend strongly on the 86 GHz flux
density and the black hole spin, but weakly on other parameters such as jet
speed, 230 GHz flux density and optical flux. The entire power budget of the
M87 jet, $\lesssim 10^{44}\rm{ergs/sec}$, can be accommodated by the tubular
jet. No invisible, powerful spine is required. Even though this analysis never
employs the resolution of the EHT, the spectral shape implies a dimension
transverse to the jet direction of 12-21 $\mu \rm{as}$ ($\sim$24-27$\, \mu
\rm{as}$) for $0.99 > a/M > 0.95$ ($a/M\sim 0.7 $), where $M$ is the mass and
$a$ is the angular momentum per unit mass of the central black hole.
