\begin{table}%t1
\caption{\label{tab:observations}Observations.}
%\centerline
{\small
\begin{tabular}{llll}
\hline
\hline
& 610 MHz & 241 MHz & 157 MHz \\
\hline
Bandpass \& flux calibrator(s) & 3C 48, 3C 147 & 3C 48, 3C 147 & 3C 48, 3C 286 \\
Phase calibrator(s)                   & 2225-049 &2225-049 & 0025-260 \\
Bandwidth		  & 32 MHz& 6 MHz$^{a}$ & 8 MHz \\
Channel width                      &125 kHz & 125 kHz &  62.5 kHz\\
Polarization			& RR& LL & RR+LL \\
Sidebands			& USB+LSB & USB & USB \\
Observation dates				& 3, 4, 5, 6 Sep. 2003& 3, 4, 5, 6 Sep. 2003 & 2, 3 Jun. 2006 \\Integration time per visibility               	& 16.9 s &16.9 s& 16.9 s \\	
Total duration$^{b}$		& 12.90 h& 12.90 h& 6.25 h\\
Beam size$^{c}$			&  $6.9\arcsec \times 4.3\arcsec$ & $17.5\arcsec \times 10.3\arcsec$ & $21.1\arcsec \times 17.1\arcsec$ \\
rms noise ($\sigma$)	& 28 $\mu$Jy beam$^{-1}$ & 297 $\mu$Jy beam$^{-1}$ & 1.36 mJy beam$^{-1}$\\	
\hline
\end{tabular}}
\par
\smallskip
$^{a}$ The total bandwidth is 16~MHz but only 6~MHz is usable due to RFI.\\
$^{b}$ On-source time (not including calibrators and slewing time).\\
$^{c}$ Restoring beam, robust weighting parameter was set to $0.5$ \citep{briggs_phd}. 
\end{table}