\begin{table}%T4
  \caption{\label{table:radio_prop}Derived parameters from the ATCA and VLA radio continuum
    observations. 
    Given are the Galactocentric  and heliocentric distance, 
    the observed frequency used
    in the calculations and the derived parameters: linear diameter, opacity,
    emission measure, electron density and number of ionizing photons
    required to maintain the ionization of the nebula.
    The IRAS luminosity
    is given in the last column.}
      %\centerline
{
    \leavevmode
    \footnotesize
    \begin{tabular}[h]{clccccclcccc} 
      \hline \hline 
    \multicolumn{2}{c}{} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{} &
    \multicolumn{5}{c}{Radio properties} & 
    \multicolumn{1}{c}{} \\[2pt] \cline{5-11} \\[-5pt]
    \multicolumn{2}{c}{Source} &
    \multicolumn{1}{c}{\rgal} &
    \multicolumn{1}{c}{\rsun} &
    \multicolumn{1}{c}{$\nu$} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{Diameter$^\dagger$} &
    \multicolumn{1}{c}{$\tau_\nu$} &
    \multicolumn{1}{c}{$EM$} &
    \multicolumn{1}{c}{\nel} &
    \multicolumn{1}{c}{log $N_{\rm Lyc}$} &
    \multicolumn{1}{c}{$L/L_{\odot}$} \\
    \multicolumn{2}{c}{} &
    \multicolumn{1}{c}{(kpc)} &
    \multicolumn{1}{c}{(kpc)} &
    \multicolumn{1}{c}{(GHz)} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{(pc)} &
    \multicolumn{1}{c}{} &
    \multicolumn{1}{c}{($10^6$ pc cm$^{-6}$)} &
    \multicolumn{1}{c}{($10^3$ \cmtrois)} &
    \multicolumn{1}{c}{(s$^{-1}$)} &
    \multicolumn{1}{c}{(10$^4$)} \\ \hline 
IRAS 01045&       &13.8& 7.0     & 8.4&& 0.16    & 0.03  &  5.2 & 5.7      & 47.82 & 4.10\\[2pt]
IRAS 10589&       & 9.5& 8.0     & 4.8&& 0.50    & 0.06  &  3.2 & 2.5      & 48.62 & 29.4\\[2pt]
IRAS 11143&       & 9.7& 8.8     & 4.8&& 2.82    & 0.005 &  0.3 & 0.3      & 49.05 & 17.1\\[2pt]
IRAS 12063&       & 9.3& 9.5     & 4.8&& 1.22    & 0.02  &  1.2 & 1.0      & 48.97 & 45.0\\[2pt]
IRAS 12073& A     &10.1&10.8     & 4.8&& 0.41    & 0.6   & 35.5 & 9.3      & ~~49.49$^\triangle$ & 400\\
...  & B     &... & ...     & ...&& 0.37    & 0.2   & 10.1 & 5.2      & 48.85 & ...\\[2pt]
IRAS 12331&       & 6.9& 4.5     & 4.8&& 1.47    & 0.006 &  0.3 & 0.5      & 48.58 & 8.45\\[2pt]
IRAS 15384&       & 6.4& 2.7     & 4.8&& 0.53  & 0.02  &  1.3 & 1.6      & 48.26 & 10.1\\[2pt]
IRAS 15502& A     & 4.5& 7.0     & 4.8&& 0.16    & 0.7   &  37.5& 15.3     &~48.68$^\star$ & 131\\
...  & B     &... & ...     & ...&& 0.08    & 0.3   &  16.7& 14.0     & 47.78 & ...\\[2pt]
IRAS 16128&       & 5.5& 3.7/11.4& 8.6&& 0.32/0.98 & 0.05  &  8.8 & 5.2/3.0  & ~~48.65/49.63$^\lhd$ & 22.8/216\\[2pt]
IRAS 17160& A     & 3.0& 5.7/11.0& 8.6&& 0.62/1.20 & 0.01   &  2.2 & 1.9/1.3  & ~~48.63/49.21$^\square$ & 35.6/133\\
...  & B     &... & $\natural$& ...&& 0.09/0.17 & 0.02   &  3.1 & 5.9/4.3  & 47.09/47.66 & ...\\
...  & C     &... & $\natural$& ...&& 0.07/0.14 & 0.02   &  3.5 & 6.9/4.9  & 47.00/47.56 & ...\\
...  & D     &... & $\natural$& ...&& 0.06/0.12 & 0.1    & 21.8 &18.9/13.6 & 47.61/48.18 & ...\\
...  & E     &... &$\natural$& ...&& 0.03/0.06 & 0.08   & 15.3 &22.4/16.1 & 46.85/47.42 & ...\\[2pt]
IRAS 17221&       & 5.2& 3.4/13.4& 4.8&& 1.10/4.35 & 0.005  &  0.3 & 0.5/0.3  & 48.25/49.44 & 7.52/117\\[2pt]
IRAS 17279& A     & 3.4& 5.1/11.8  & 8.6&& 0.49/1.14& 0.003 &  0.6 & 1.1/0.7  & ~~47.88/48.61$^\boxplus$ & 10.4/55.9\\
...  & B     &... & $\natural$& 4.8&& 0.07/0.15& 0.1   &  6.3 & 9.7/6.4  & 47.15/47.88 & ...\\
...  & C     &... & $\natural$& ...&& 0.08/0.19& 0.09  &  4.8 & 7.6/5.0  & 47.23/47.96 & ...\\[2pt]
IRAS 18032& B     & 3.0& 5.7     & 8.4&& 0.38    & 0.006 & 1.1  & 1.7  &~47.92$^\oplus$ & 32.3\\
...     & C     &... & ...     & ...&& 0.11    & 0.01  & 2.1  & 4.3  &47.11 & ...\\
...     & D     &... & ...     & ...&& 0.03    & 0.2   & 31.2 & 33.6 &47.08 & ...\\[2pt]
IRAS 18479&A      & 7.4& 13.0    & 8.4&& 0.30    & 0.1   & 27.0 & 9.4      &~49.10$^\Diamond$ & 147\\
...     &B      &... & ...     & ...&& 0.09    & 0.6   &119.9 & 35.5     &48.74& ...\\ [2pt]
IRAS 19442&core    & 7.7&  2.0    & 8.4&& 0.01    & 0.08  & 14.6 & 34.8     &~46.45$^\rhd$ & 3.39\\
...  & halo       &...&  ...    & ...&& 0.11    & 0.002 & 0.3  & 1.6      & ... & ...\\[2pt]
IRAS 19598&       & 9.6&  8.2    & 8.4&& 0.25    & 0.3   & 44.3 & 13.4     & 49.14 & 187\\[2pt]
DR21 &A      & 8.6&  2.8    & 8.4&& 0.05    & 0.1   & 20.5 & 20.4     &47.39 & $^c$\\
...  &B      & ...&  ...    & ...&& 0.06    & 0.1   & 21.1 & 18.8     &47.58 & ...\\[2pt]
IRAS 23133&       &12.6&  6.7    & 8.4&& 0.2     & 0.02  & 4.3  & 4.2       & 48.10 & 27.5
\\[5pt] \hline 
     \end{tabular}}
\smallskip
{
$^\dagger$ Diameter in pc of the sphere assumed to be representative
of  the source (see Sect.~\ref{sect:radio:prop}).
$^\triangle$ $10^{49.95}$~photons~s$^{-1}$ are required to ionize the
whole nebula, including the contribution of the low brightness emission.
$^\star$~$10^{48.73}$~photons~s$^{-1}$ are required to ionize both
components~A and~B.
$^\lhd$~$10^{48.83}$/$10^{49.80}$~photons~s$^{-1}$ result when the
total~4.8~GHz flux density is considered.
$^\square$~$10^{48.97}$/$10^{49.54}$ result when the total 4.8~GHz
flux density integrated over the whole field is considered.
$^\boxplus$~$10^{48.32}$/$10^{49.05}$~photons~s$^{-1}$ result when 
the total 4.8~GHz flux density
integrated over the whole field is considered.
$^\oplus$~The added contribution of the 3~components~A, B and~C is~$10^{48.03}$~photons~s$^{-1}$. 
$^\natural$~We consider it to be located at the same distance than the IRAS~source.
$^\Diamond$~$10^{49.40}$~photons~s$^{-1}$ are required to ionize the
whole nebula.
$^\rhd$~Lymann continuum flux required to mantain the ionization of
the whole nebula.
$^\flat$~The added contribution of the 2~components~A and~B
is~$10^{47.80}$~photons~s$^{-1}$. 
$^c$~No IRAS fluxes avalaible.
}
\end{table}