\begin{table}%T4
\caption{Flux density values of the relic.}
\small%\centerline
{
\begin{tabular}{lccc}
\hline\hline\noalign{\smallskip}
$\nu$ & $S_{\nu}$ & {\it HPWB} & Ref. \\
 (MHz) & (mJy) & $^{\prime \prime} \times^{\prime \prime}$ & \\
\hline\noalign{\smallskip}
74  & 660 & 80.0 $\times$ 80.0  & VLSS \\
235 & 180 $\pm$ 10 & 15.6 $\times$ 12.4 & see Appendix \\
327 & 114 $\pm$ 6  & 16.0 $\times$ 13.0  & this work; Fig.~\ref{fig:relic327} \\
610 & 42 $\pm$ 2    & 13.0 $\times$ 8.1   & GVB06  \\
1410 & 14 $\pm$ 1   & 15.0 $\times$ 12.0  & Giacintucci (\cite{giacintucci07}) $^{\star}$ \\
4890 & 2.0 $\pm$ 0.2 & 22.0 $\times$ 15.0 & this work; Fig.~\ref{fig:a521_relic4.9} \\
\hline 
\end{tabular}}
\smallskip
$\star$ From VLA-CnB archival data (Obs. Id. AF~0390).
\label{tab:a521_relic}
\end{table}