\begin{table}%t4 \caption{\label{table:4}Details of EVN observations.} %\centerline { \begin{tabular}{cccccccc} \hline\hline Observing & Date & Duration& Telescopes$^*$ & Cycle time & Spectral channel & Synthesized & Rms noise\\ run & & & & & separation & beam($\alpha\times\delta$; PA)& per channel\\ & & (h) & & (min) & (km~s$^{-1}$)& (mas~$\times$~mas;\degr)& (mJy~beam$^{-1}$)\\ \hline 1 & 2003 Jun. 08& 12& CmJbEfOn & 6.00$+$4.00& 0.09 &6~$\times$~16; $-$1& 10\\ 2 & 2004 Nov. 11& 12& CmDaEfMcNtOnTrWb & 3.75$+$1.75& 0.09 &6~$\times$~16; $+$7& 4\\ 3a & 2006 Feb. 22& 10& CmJbEfHhMcNtOnWb & 3.75$+$1.75& 0.09 &5~$\times$~15;$+$31& 10\\ 3b & 2006 Feb. 23& 10& CmJbEfHhMcOnWb & 3.75$+$1.75& 0.09 &6~$\times$~14;$+$34& 7\\ 4a & 2007 Jun. 13& 10& CmJbEfHhMcNtOnTrWb& 3.25$+$1.75& 0.18 &6~$\times$~12;$+$20& 4\\ 4b & 2007 Jun. 14& 10& CmJbEfHhMcNtOnTrWb& 3.25$+$1.75& 0.18 &6~$\times$~11;$+$25& 4\\ 4c & 2007 Jun. 15& 10& CmJbEfMcNtOnTrWb & 3.25$+$1.75& 0.09 &6~$\times$~13;$+$35& 6\\ \hline \end{tabular} } \smallskip $^*$ Cm-Cambridge, Da-Darnhall, Jb-Jodrell Bank, Ef-Effelsberg, Hh-Hartebeesthoek, Mc-Medicina, Nt-Noto, On-Onsala, Tr-Toru\'n, \mbox{Wb-Westerbork}. \par \end{table}