\begin{table}%t2
\caption{\label{tabaging}Estimates of ages of the eleven radio galaxies.}       
\small%\centerline
 {
\begin{tabular}{lrrrrrrrr}         
\hline\hline                  
Source & Side & $\alpha_{\rm hs} $ & $\alpha_{\rm final} $ & $\theta$ & $\nu_{0T}$ &
$B_{\rm min}$ & $t_{(b=1)}$ & $t_{(b=0.25)}$ \\
      &  &  &  & arcsec & GHz & $\mu$ G & Myr  & Myr \\
\hline                         
3C 
6.1  &       N       &       0.84    &       1.37    &       9.5     &$ 
   10.6    \pm     2.9     $&$     50.8    \pm     0.6     $&$     1.0 
\pm     0.1
$&$     4       \pm     1$      \\
3C 
6.1  &       S       &       0.82    &       1.34    &       9       &$ 
   12.6    \pm     3.7     $&$     39.2    \pm     0.6     $&$     1.2 
\pm     0.2
$&$     5       \pm     1       $\\
3C 
34   &       E       &       0.81    &       1.72    &       20      &$ 
   5.6     \pm     0.6     $&$     28      \pm     0.4     $&$     3.2 
\pm     0.2     $&$
10      \pm     1       $\\
3C 
34   &       W       &       0.84    &       1.95    &       18.5    &$ 
   4.5     \pm     0.4     $&$     27.6    \pm     0.3     $&$     3.5 
\pm     0.2
$&$     12      \pm     1       $\\
3C 
41   &       N       &       0.71    &       1.42    &       10      &$ 
   6.6     \pm     1.4     $&$     30.2    \pm     0.9     $&$     2.5 
\pm     0.3     $&$
8       \pm     1       $\\
3C 
41   &       S       &       0.52    &       1.57    &       11      &$ 
   3.5     \pm     0.3     $&$     45      \pm     0.4     $&$     2.0 
\pm     0.1     $&$     9
\pm     1       $\\
3C 
44   &       N       &       0.89    &       1.97    &       30.5    &$ 
   4.1     \pm     0.6     $&$     40      \pm     1       $&$     2.3 
\pm     0.2     $&$
11      \pm     2       $\\
3C 
44   &       S       &       0.90    &       2.03    &       19      &$ 
   3.7     \pm     0.4     $&$     39.5    \pm     0.7     $&$     2.5 
\pm     0.2     $&$
12      \pm     2       $\\
3C 
54   &       N       &       0.74    &       1.5     &       21      &$ 
   6.4     \pm     1.1     $&$     32      \pm     1       $&$     2.4 
\pm     0.2     $&$     7
\pm     1       $\\
3C 
54   &       S       &       0.78    &       1.98    &       15.5    &$ 
   3.3     \pm     0.4     $&$     48.4    \pm     0.2     $&$     1.8 
\pm     0.1
$&$     9       \pm     1       $\\
3C 
114  &       N       &       0.82    &       2.07    &       19.5    &$ 
   3.3     \pm     0.3     $&$     28.2    \pm     0.1     $&$     3.8 
\pm     0.1
$&$     11      \pm     1       $\\
3C 
114  &       S       &       0.84    &       1.82    &       22.5    &$ 
   4.1     \pm     0.6     $&$     27.4    \pm     0.3     $&$     3.5 
\pm     0.2
$&$     10      \pm     1       $\\
3C 
142.1        &       N       &       0.89    &       1.75    &       13.5 
   &$      5.5     \pm     0.9     $&$     39.6    \pm     0.1     $&$ 
2.2     \pm
0.2
$&$     13      \pm     2       $\\
3C 
142.1        &       S       &       0.81    &       1.2     &       30 
   &$      13      \pm     4       $&$     25.7    \pm     0.5     $&$ 
2.7     \pm     0.4     $&$
12      \pm     2       $\\
3C 
169.1        &       N       &       0.79    &       1.33    &       16 
   &$      9.3     \pm     2.5     $&$     19.8    \pm     0.1     $&$ 
3.9     \pm     0.5
$&$     9       \pm     1       $\\
3C 
169.1        &       S       &       0.77    &       1.5     &       23.5 
   &$      6.3     \pm     1.4     $&$     25.8    \pm     0.1     $&$ 
3.4     \pm     0.4
$&$     11      \pm     2       $\\
3C 
172  &       N       &       0.91    &       1.22    &       20      &$ 
   21      \pm     9       $&$     28.6    \pm     0.6     $&$     1.7 
\pm     0.3     $&$
7       \pm     2       $\\
3C 
172  &       S       &       0.88    &       1.01    &       21.5    &$ 
   86      \pm     83      $&$     25      \pm     1       $&$     1.1 
\pm     0.5     $&$
4       \pm     1.5$\\
3C 
441  &       N       &       0.65    &       1.1     &       5       &$ 
   9.6     \pm     2       $&$     27.6    \pm     0.2     $&$     2.4 
\pm     0.2     $&$
8       \pm     1       $\\
3C 
441  &       S       &       0.95    &       1.35    &       16.5    &$ 
   17      \pm     6       $&$     37.8    \pm     0.7     $&$     1.2 
\pm     0.2     $&$
5       \pm     1       $\\
3C 
469.1        &       N       &       1.11    &       1.76    &       10.5 
   &$      9.8     \pm     2.1     $&$     65      \pm     4       $&$ 
0.6     \pm     0.1
$&$     2.4     \pm     0.3     $\\
3C 
469.1        &       S       &       0.95    &       1.96    &       14.5 
   &$      4.6     \pm     0.7     $&$     57.3    \pm     0.5     $&$ 
1.0     \pm
0.1
$&$     3.6     \pm     0.3     $\\
\hline
\end{tabular}}
\medskip
Column~1: source name. Column 2: side of the source on which the spectral aging was determined. Column~3: the spectral index of the hotspot between 20 and 6~cm. This is adopted as the injection spectral index for the electrons in the lobe. Column~4: the spectral index in the lobe furthest from the hot spot along the brightness ridge line. The errors in hotspot and lobe spectral index are likely dominated by systematic errors rather than by thermal noise and are estimated to be $\sim$$0.1$. Note that any constant multiplicative error on the flux density (e.g., due to an absolute flux density calibration error) will subtract out when the difference between the hotspot
and lobe spectral index is determined.  Column~5: the distance from the hotspot to the location of
the maximum spectral index. The estimated error is of order 1~arcsec.  Column~6: the estimated break
frequency. Column~7: the equipartition magnetic field in the lobe obtained from $B_{\rm min} =
(B_{10}B_{25})^{0.5}$ using the minimum energy fields obtained at distances of 10 and 25~kpc 
from the hotspot along the ridge line towards the nucleus.  Column~8: the radiative loss age at the distance~$\theta$ from the hotspot,  assuming the magnetic field is equal to the minimum energy value. Column~9: the radiative loss age at the distance~$\theta$ from the hotspot, assuming the magnetic field is equal to~1/4 of the minimum energy value.
\end{table}