\documentstyle[aj_pt4]{article}
\begin{document}
\pagestyle{empty}

% Table 3, post-flare radio
\begin{deluxetable}{llll}
\tablenum{3}
\tablecaption{Radio flux densities after the $\gamma$--ray flare.}
\tablehead{
\colhead{Date} & \colhead{Freq.}  & \colhead{Flux density}  
 & \colhead{Source of data} \\ 
\colhead{}     & \colhead{(GHz)}  & \colhead{(Jy)}         
 & \colhead{}
}
\startdata
1998 Aug 05 & 1.6  & $1.01\pm0.03$ & ATCA\\
1998 Aug 05 & 2.3  & $1.67\pm0.03$ & ATCA\\
1998 Aug 05 & 4.8  & $3.61\pm0.04$ & ATCA\\    
1998 Aug 05 & 8.6  & $6.57\pm0.07$ & ATCA\\ 
1998 Aug 14 & 90   & $7.02\pm0.40$  & SEST\\
1998 Aug 14 & 230  & $3.50\pm0.34$  & SEST\\
1998 Dec 30 & 90   & $7.21\pm0.42$  & SEST\\
1998 Dec 30 & 115  & $6.06\pm0.69$  & SEST\\
1998 Dec 30 & 150  & $5.39\pm0.49$  & SEST\\
\enddata
\tablecomments{The data are from SEST and ATCA (this paper).}
\end{deluxetable}

\end{document}

