\begin{table}%t1
  \caption{Characteristics of emission lines.}
  \label{t_lin_v2051oph}
  %\centering
\par
  \begin{tabular}{llll}
    \hline\hline
    & $FWZI$ & $EW$ & Integrated flux\\
    & [km~s$^{-1}$] & [\AA] & [$10^{-13}$ erg cm$^{-2}$ s$^{-1}$]\\
    \hline
    H$\delta$ & 5695 & 60.3 & 6.5\\
    H$\gamma$ & 5945 & 78.4 & 6.7\\
    \ion{He}{i}  $\lambda$4471 & 4630 & 27.3 & 2.3\\
    H$\beta$  & 5395 & 94.8 & 7.5\\
    \ion{He}{i}  $\lambda$4922+\ion{Fe}{ii} $\lambda$4924 & 3199 & 11.4 & 0.88\\
    \ion{He}{i} $\lambda$5016+\ion{Fe}{ii} $\lambda$5018 & 3296 & 14.5 & 1.1\\
    \ion{Fe}{ii} $\lambda$5169 & 3472 & 9.8 & 0.68\\
    \ion{He}{i}  $\lambda$5876 & 3043 & 35.9 & 2.3\\
    H$\alpha$ & 4428 & 140.5 & 8.1\\
    \ion{He}{i}  $\lambda$6678 & 3503 & 26.3 & 1.5\\
    \ion{He}{i}  $\lambda$7065 & 3223 & 19.0 & 1.0\\
    \hline
  \end{tabular}
\end{table}