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% Table 4, VLBI data
\begin{deluxetable}{llllllllll} 
\tablenum{4}
\tablecaption{VLBI data.}
\tablehead{
\colhead{Freq.} & \colhead{S} & \colhead{R} & \colhead{P.A.}& \colhead{a} &
  \colhead{b/a} & \colhead{$\phi$} & \colhead{$T_{b,G}$} & 
  \colhead{$T_{b,ThinS}$} & \colhead{$T_{b,ThickS}$} \\
\colhead{(GHz)} & \colhead{(Jy)} & \colhead{(mas)} & \colhead{(deg)} &
  \colhead{(mas)} & \colhead{} & \colhead{(deg)} &
  \colhead{($10^{12}$ K)} & \colhead{($10^{12}$ K)} & 
  \colhead{($10^{12}$ K)}
}
\startdata
5&2.83& 0.00& --& 0.37& 0.59& 21.3&2.3 &1.0 &0.8 \\
&0.25& 3.81& -138.3& 1.90& 0.18& 58.1& & & \\ 
22& 4.24& 0.00& --&  0.14& 0.29& 68.0&3.6 &1.6& 1.3 \\ 
43& 2.75& 0.00& --&  0.13& 0.57& 65.2&  0.4 &0.2 &0.1 \\ 
\enddata
\tablecomments{The VLBI data are from 1997 August 13.
Freq. is the observing frequency; S is the total flux density
of the model component; R is the distance of the component centroid
from the core (core fixed at R=0); P.A. is the position angle of the
component relative to the core (core fixed at P.A.=0); a is the
semi-major axis (FWHM) of the Gaussian model component; b/a is the
axial semi-minor to semi-major axis ratio for the Gaussian model
component; $\phi$ is the position angle of the semi-major axis of the
model component; $T_{b,G}$ is the brightness temperature calculated
from the Gaussian model component; $T_{b,ThinS}$ is the brightness
temperature calculated for an optically thin sphere model component
(calculated using a correction to $T_{b,G}$); $T_{b,ThickS}$ is the
brightness temperature calculated for an optically thick sphere model
component (calculated using a correction to $T_{b,G}$).}
\end{deluxetable}

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